XML 69 R54.htm IDEA: XBRL DOCUMENT v3.3.1.900
Debt (Summary Of Company's Senior Notes) (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Debt Instrument    
Senior note carrying value $ 1,584,769 $ 1,818,561
Estimated fair value $ 1,643,651 $ 1,952,774
Unsecured Senior Notes 5.20% Due February 2015 [Member]    
Debt Instrument    
Debt instrument, interest rate, stated percentage 5.20% 5.20%
Debt instrument, maturity date, description February 2015 February 2015
Unsecured Senior Notes 5.25% Due June 2015 [Member]    
Debt Instrument    
Senior note carrying value $ 0 $ 236,452
Debt instrument, interest rate, stated percentage 5.25% 5.25%
Debt instrument, maturity date, description June 2015 June 2015
Unsecured Senior Notes 6.50% Due May 2016 [Member]    
Debt Instrument    
Senior note carrying value $ 464,436 $ 462,009
Debt instrument, interest rate, stated percentage 6.50% 6.50%
Debt instrument, maturity date, description May 2016 May 2016
Unsecured Senior Notes 7.625% Due October 2017 [Member]    
Debt Instrument    
Senior note carrying value $ 122,841 $ 122,752
Debt instrument, interest rate, stated percentage 7.625% 7.625%
Debt instrument, maturity date, description October 2017 October 2017
Unsecured Senior Notes 7.875% Due June 2032 [Member]    
Debt Instrument    
Senior note carrying value $ 299,283 $ 299,239
Debt instrument, interest rate, stated percentage 7.875% 7.875%
Debt instrument, maturity date, description June 2032 June 2032
Unsecured Senior Notes 6.375% Due May 2033 [Member]    
Debt Instrument    
Senior note carrying value $ 398,714 $ 398,640
Debt instrument, interest rate, stated percentage 6.375% 6.375%
Debt instrument, maturity date, description May 2033 May 2033
Unsecured Senior Notes 6.00% Due February 2035 [Member]    
Debt Instrument    
Senior note carrying value $ 299,495 $ 299,469
Debt instrument, interest rate, stated percentage 6.00% 6.00%
Debt instrument, maturity date, description February 2035 February 2035
Unsecured Senior Notes 7.375% Due June 2046 [Member]    
Debt Instrument    
Debt instrument, interest rate, stated percentage 7.375% 7.375%
Debt instrument, maturity date, description June 2046 June 2046