Annual report pursuant to Section 13 and 15(d)

Senior Unsecured Notes (Summary Of Senior Unsecured Notes) (Details)

v3.3.1.900
Senior Unsecured Notes (Summary Of Senior Unsecured Notes) (Details) - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Dec. 31, 2014
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Debt Instrument [Line Items]        
Senior Unsecured Notes $ 1,267,744 $ 1,268,844 $ 1,267,744  
Loss from early extinguishment of debt 582   582 $ 156
5.800% Senior Unsecured Notes, Due January 15, 2016 [Member]        
Debt Instrument [Line Items]        
Senior Unsecured Notes [1] 200,086 $ 200,010 200,086  
Effective rate [1],[2]   5.806%    
Interest rate of senior unsecured notes [1]   5.80%    
Maturity date of the senior unsecured notes [1]   Jan. 15, 2016    
2.500% Senior Unsecured Notes Due December 15, 2017 [Member]        
Debt Instrument [Line Items]        
Senior Unsecured Notes 249,150 $ 249,446 249,150  
Effective rate [2]   2.803%    
Interest rate of senior unsecured notes   2.50%    
Maturity date of the senior unsecured notes   Dec. 15, 2017    
7.750% Senior Unsecured Notes, Due August 15, 2019 [Member]        
Debt Instrument [Line Items]        
Senior Unsecured Notes 249,013 $ 249,227 249,013  
Effective rate [2]   8.017%    
Interest rate of senior unsecured notes   7.75%    
Maturity date of the senior unsecured notes   Aug. 15, 2019    
4.500% Senior Unsecured Notes Due April 18, 2022 [Member]        
Debt Instrument [Line Items]        
Senior Unsecured Notes 299,565 $ 299,624 299,565  
Effective rate [2]   4.612%    
Interest rate of senior unsecured notes   4.50%    
Maturity date of the senior unsecured notes   Apr. 18, 2022    
3.150% Senior Unsecured Notes, Due May 15, 2023 [Member]        
Debt Instrument [Line Items]        
Senior Unsecured Notes $ 269,930 $ 270,537 $ 269,930  
Effective rate [2]   3.517%    
Interest rate of senior unsecured notes   3.15%    
Maturity date of the senior unsecured notes   May 15, 2023    
[1] On January 15, 2016, the Company repaid these notes at their maturity using proceeds from a new unsecured term loan and borrowings under the Company's unsecured revolving credit facility.
[2] Includes the cost of terminated treasury lock agreements (if any), offering and other transaction costs and the discount/premium on the notes, as applicable.