Annual report pursuant to Section 13 and 15(d)

Segment Reporting (Selected Results Of Operations And Asset Information) (Details)

v2.4.1.9
Segment Reporting (Selected Results Of Operations And Asset Information) (Details) (USD $)
 3 Months Ended 12 Months Ended
Dec. 31, 2014
Sep. 30, 2014
Jun. 30, 2014
Mar. 31, 2014
Dec. 31, 2013
Sep. 30, 2013
Jun. 30, 2013
Mar. 31, 2013
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Segment Reporting Information [Line Items]                      
Total revenues $ 151,414,000us-gaap_RealEstateRevenueNet $ 155,489,000us-gaap_RealEstateRevenueNet $ 160,300,000us-gaap_RealEstateRevenueNet $ 169,596,000us-gaap_RealEstateRevenueNet $ 165,267,000us-gaap_RealEstateRevenueNet $ 162,505,000us-gaap_RealEstateRevenueNet $ 168,346,000us-gaap_RealEstateRevenueNet $ 170,913,000us-gaap_RealEstateRevenueNet $ 636,799,000us-gaap_RealEstateRevenueNet $ 667,031,000us-gaap_RealEstateRevenueNet $ 650,632,000us-gaap_RealEstateRevenueNet
Total operating and interest expenses                 484,761,000cli_OperatingAndInterestExpenses [1] 460,615,000cli_OperatingAndInterestExpenses [1] 428,017,000cli_OperatingAndInterestExpenses
Equity in earnings (loss) of unconsolidated joint ventures (363,000)us-gaap_IncomeLossFromEquityMethodInvestments (1,268,000)us-gaap_IncomeLossFromEquityMethodInvestments 443,000us-gaap_IncomeLossFromEquityMethodInvestments (1,235,000)us-gaap_IncomeLossFromEquityMethodInvestments (268,000)us-gaap_IncomeLossFromEquityMethodInvestments (229,000)us-gaap_IncomeLossFromEquityMethodInvestments (80,000)us-gaap_IncomeLossFromEquityMethodInvestments (1,750,000)us-gaap_IncomeLossFromEquityMethodInvestments (2,423,000)us-gaap_IncomeLossFromEquityMethodInvestments (2,327,000)us-gaap_IncomeLossFromEquityMethodInvestments 4,089,000us-gaap_IncomeLossFromEquityMethodInvestments
Net operating income (loss)                 149,615,000cli_SegmentReportingInformationNetOperatingIncomeLossForReportableSegment [2] 204,089,000cli_SegmentReportingInformationNetOperatingIncomeLossForReportableSegment 226,704,000cli_SegmentReportingInformationNetOperatingIncomeLossForReportableSegment [2]
Total assets 4,192,247,000us-gaap_Assets       4,515,328,000us-gaap_Assets       4,192,247,000us-gaap_Assets 4,515,328,000us-gaap_Assets  
Total long-lived assets 3,670,704,000cli_LongLivedAssets [3]       3,868,193,000cli_LongLivedAssets [3]       3,670,704,000cli_LongLivedAssets [3] 3,868,193,000cli_LongLivedAssets [3]  
Investments in unconsolidated joint ventures 247,468,000us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures       181,129,000us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures       247,468,000us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures 181,129,000us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures  
Real Estate - Commercial And Other [Member]                      
Segment Reporting Information [Line Items]                      
Total revenues                 585,491,000us-gaap_RealEstateRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateCommercialAndOtherSegmentMember 		621,352,000us-gaap_RealEstateRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateCommercialAndOtherSegmentMember 		635,278,000us-gaap_RealEstateRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateCommercialAndOtherSegmentMember
Total operating and interest expenses                 295,416,000cli_OperatingAndInterestExpenses
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateCommercialAndOtherSegmentMember 		[1] 285,755,000cli_OperatingAndInterestExpenses
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateCommercialAndOtherSegmentMember 		[1] 276,700,000cli_OperatingAndInterestExpenses
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateCommercialAndOtherSegmentMember
Equity in earnings (loss) of unconsolidated joint ventures                 4,236,000us-gaap_IncomeLossFromEquityMethodInvestments
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateCommercialAndOtherSegmentMember 		6,280,000us-gaap_IncomeLossFromEquityMethodInvestments
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateCommercialAndOtherSegmentMember 		5,564,000us-gaap_IncomeLossFromEquityMethodInvestments
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateCommercialAndOtherSegmentMember
Net operating income (loss)                 294,311,000cli_SegmentReportingInformationNetOperatingIncomeLossForReportableSegment
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateCommercialAndOtherSegmentMember 		[2] 341,877,000cli_SegmentReportingInformationNetOperatingIncomeLossForReportableSegment
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateCommercialAndOtherSegmentMember 		364,142,000cli_SegmentReportingInformationNetOperatingIncomeLossForReportableSegment
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateCommercialAndOtherSegmentMember 		[2]
Total assets 3,636,126,000us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateCommercialAndOtherSegmentMember 		      3,886,574,000us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateCommercialAndOtherSegmentMember 		      3,636,126,000us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateCommercialAndOtherSegmentMember 		3,886,574,000us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateCommercialAndOtherSegmentMember 		 
Total long-lived assets 3,344,840,000cli_LongLivedAssets
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateCommercialAndOtherSegmentMember 		[3]       3,620,494,000cli_LongLivedAssets
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateCommercialAndOtherSegmentMember 		[3]       3,344,840,000cli_LongLivedAssets
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateCommercialAndOtherSegmentMember 		[3] 3,620,494,000cli_LongLivedAssets
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateCommercialAndOtherSegmentMember 		[3]  
Investments in unconsolidated joint ventures 81,649,000us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateCommercialAndOtherSegmentMember 		      53,160,000us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateCommercialAndOtherSegmentMember 		      81,649,000us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateCommercialAndOtherSegmentMember 		53,160,000us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateCommercialAndOtherSegmentMember 		 
Real Estate - Multi Family [Member]                      
Segment Reporting Information [Line Items]                      
Total revenues                 24,971,000us-gaap_RealEstateRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateMultipleFamilySegmentMember 		12,792,000us-gaap_RealEstateRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateMultipleFamilySegmentMember 		 
Total operating and interest expenses                 12,235,000cli_OperatingAndInterestExpenses
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateMultipleFamilySegmentMember 		[1] 6,482,000cli_OperatingAndInterestExpenses
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateMultipleFamilySegmentMember 		[1]  
Equity in earnings (loss) of unconsolidated joint ventures                 (8,790,000)us-gaap_IncomeLossFromEquityMethodInvestments
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateMultipleFamilySegmentMember 		(10,615,000)us-gaap_IncomeLossFromEquityMethodInvestments
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateMultipleFamilySegmentMember 		(1,475,000)us-gaap_IncomeLossFromEquityMethodInvestments
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateMultipleFamilySegmentMember
Net operating income (loss)                 3,946,000cli_SegmentReportingInformationNetOperatingIncomeLossForReportableSegment
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateMultipleFamilySegmentMember 		[2] (4,305,000)cli_SegmentReportingInformationNetOperatingIncomeLossForReportableSegment
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateMultipleFamilySegmentMember 		(1,475,000)cli_SegmentReportingInformationNetOperatingIncomeLossForReportableSegment
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateMultipleFamilySegmentMember 		[2]
Total assets 492,362,000us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateMultipleFamilySegmentMember 		      377,237,000us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateMultipleFamilySegmentMember 		      492,362,000us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateMultipleFamilySegmentMember 		377,237,000us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateMultipleFamilySegmentMember 		 
Total long-lived assets 318,524,000cli_LongLivedAssets
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateMultipleFamilySegmentMember 		[3]       240,501,000cli_LongLivedAssets
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateMultipleFamilySegmentMember 		[3]       318,524,000cli_LongLivedAssets
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateMultipleFamilySegmentMember 		[3] 240,501,000cli_LongLivedAssets
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateMultipleFamilySegmentMember 		[3]  
Investments in unconsolidated joint ventures 164,912,000us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateMultipleFamilySegmentMember 		      127,276,000us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateMultipleFamilySegmentMember 		      164,912,000us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateMultipleFamilySegmentMember 		127,276,000us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures
/ us-gaap_StatementBusinessSegmentsAxis
= cli_RealEstateMultipleFamilySegmentMember 		 
Multi Family Services [Member]                      
Segment Reporting Information [Line Items]                      
Total revenues                 30,533,000us-gaap_RealEstateRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= cli_MultipleFamilyServicesSegmentMember 		[4] 25,710,000us-gaap_RealEstateRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= cli_MultipleFamilyServicesSegmentMember 		[5] 4,465,000us-gaap_RealEstateRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= cli_MultipleFamilyServicesSegmentMember
Total operating and interest expenses                 38,377,000cli_OperatingAndInterestExpenses
/ us-gaap_StatementBusinessSegmentsAxis
= cli_MultipleFamilyServicesSegmentMember 		[1] 32,415,000cli_OperatingAndInterestExpenses
/ us-gaap_StatementBusinessSegmentsAxis
= cli_MultipleFamilyServicesSegmentMember 		[1] 5,195,000cli_OperatingAndInterestExpenses
/ us-gaap_StatementBusinessSegmentsAxis
= cli_MultipleFamilyServicesSegmentMember
Equity in earnings (loss) of unconsolidated joint ventures                 2,131,000us-gaap_IncomeLossFromEquityMethodInvestments
/ us-gaap_StatementBusinessSegmentsAxis
= cli_MultipleFamilyServicesSegmentMember 		2,008,000us-gaap_IncomeLossFromEquityMethodInvestments
/ us-gaap_StatementBusinessSegmentsAxis
= cli_MultipleFamilyServicesSegmentMember 		 
Net operating income (loss)                 (5,713,000)cli_SegmentReportingInformationNetOperatingIncomeLossForReportableSegment
/ us-gaap_StatementBusinessSegmentsAxis
= cli_MultipleFamilyServicesSegmentMember 		[2] (4,697,000)cli_SegmentReportingInformationNetOperatingIncomeLossForReportableSegment
/ us-gaap_StatementBusinessSegmentsAxis
= cli_MultipleFamilyServicesSegmentMember 		(730,000)cli_SegmentReportingInformationNetOperatingIncomeLossForReportableSegment
/ us-gaap_StatementBusinessSegmentsAxis
= cli_MultipleFamilyServicesSegmentMember 		[2]
Total assets 11,158,000us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= cli_MultipleFamilyServicesSegmentMember 		      10,488,000us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= cli_MultipleFamilyServicesSegmentMember 		      11,158,000us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= cli_MultipleFamilyServicesSegmentMember 		10,488,000us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= cli_MultipleFamilyServicesSegmentMember 		 
Total long-lived assets 3,858,000cli_LongLivedAssets
/ us-gaap_StatementBusinessSegmentsAxis
= cli_MultipleFamilyServicesSegmentMember 		[3]       3,468,000cli_LongLivedAssets
/ us-gaap_StatementBusinessSegmentsAxis
= cli_MultipleFamilyServicesSegmentMember 		[3]       3,858,000cli_LongLivedAssets
/ us-gaap_StatementBusinessSegmentsAxis
= cli_MultipleFamilyServicesSegmentMember 		[3] 3,468,000cli_LongLivedAssets
/ us-gaap_StatementBusinessSegmentsAxis
= cli_MultipleFamilyServicesSegmentMember 		[3]  
Investments in unconsolidated joint ventures 907,000us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures
/ us-gaap_StatementBusinessSegmentsAxis
= cli_MultipleFamilyServicesSegmentMember 		      693,000us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures
/ us-gaap_StatementBusinessSegmentsAxis
= cli_MultipleFamilyServicesSegmentMember 		      907,000us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures
/ us-gaap_StatementBusinessSegmentsAxis
= cli_MultipleFamilyServicesSegmentMember 		693,000us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures
/ us-gaap_StatementBusinessSegmentsAxis
= cli_MultipleFamilyServicesSegmentMember 		 
Fee revenue                 2,300,000us-gaap_PropertyManagementFeeRevenue
/ us-gaap_StatementBusinessSegmentsAxis
= cli_MultipleFamilyServicesSegmentMember 		2,200,000us-gaap_PropertyManagementFeeRevenue
/ us-gaap_StatementBusinessSegmentsAxis
= cli_MultipleFamilyServicesSegmentMember 		 
Corporate & Other [Member]                      
Segment Reporting Information [Line Items]                      
Total revenues                 (4,196,000)us-gaap_RealEstateRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_CorporateAndOtherMember 		[6] 7,177,000us-gaap_RealEstateRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_CorporateAndOtherMember 		[6] 10,889,000us-gaap_RealEstateRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_CorporateAndOtherMember 		[6]
Total operating and interest expenses                 138,733,000cli_OperatingAndInterestExpenses
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_CorporateAndOtherMember 		[1],[6] 135,963,000cli_OperatingAndInterestExpenses
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_CorporateAndOtherMember 		[1],[6] 146,122,000cli_OperatingAndInterestExpenses
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_CorporateAndOtherMember 		[6]
Net operating income (loss)                 (142,929,000)cli_SegmentReportingInformationNetOperatingIncomeLossForReportableSegment
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_CorporateAndOtherMember 		[2],[6] (128,786,000)cli_SegmentReportingInformationNetOperatingIncomeLossForReportableSegment
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_CorporateAndOtherMember 		[6] (135,233,000)cli_SegmentReportingInformationNetOperatingIncomeLossForReportableSegment
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_CorporateAndOtherMember 		[2],[6]
Total assets 52,601,000us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_CorporateAndOtherMember 		[6]       241,029,000us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_CorporateAndOtherMember 		[6]       52,601,000us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_CorporateAndOtherMember 		[6] 241,029,000us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_CorporateAndOtherMember 		[6]  
Total long-lived assets $ 3,482,000cli_LongLivedAssets
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_CorporateAndOtherMember 		[3],[6]       $ 3,730,000cli_LongLivedAssets
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_CorporateAndOtherMember 		[3],[6]       $ 3,482,000cli_LongLivedAssets
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_CorporateAndOtherMember 		[3],[6] $ 3,730,000cli_LongLivedAssets
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_CorporateAndOtherMember 		[3],[6]  
[1] Total operating and interest expenses represent the sum of: real estate taxes; utilities; operating services; direct construction costs; real estate services expenses; general and administrative and interest expense (net of interest income). All interest expense, net of interest and other investment income, (including for property-level mortgages) is excluded from segment amounts and classified in Corporate & Other for all periods.
[2] Net operating income represents total revenues less total operating and interest expenses (as defined in Note “a”), plus equity in earnings (loss) of unconsolidated joint ventures, for the period.
[3] Long-lived assets are comprised of net investment in rental property, unbilled rents receivable and goodwill.
[4] Includes $2.3 million of fees earned for this period from the multi-family real estate segment, which are eliminated in consolidation.
[5] Includes $2.2 million of fees earned for this period from the multi-family real estate segment, which are eliminated in consolidation.
[6] Corporate & Other represents all corporate-level items (including interest and other investment income, interest expense, non-property general and administrative expense, construction services revenue and direct construction costs) as well as intercompany eliminations necessary to reconcile to consolidated Company totals.