Debt and Other Obligations (Indebtedness) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Total debt and other obligations	$ 1,500,000	$ 1,500,000
2012 secured notes tranche A [Member]
Debt Instrument [Line Items]
Total debt and other obligations	$ 500,000
Stated interest rate	2.381%
2012 secured notes tranche B [Member]
Debt Instrument [Line Items]
Total debt and other obligations	$ 1,000,000
Stated interest rate	3.849%
2012 Secured Notes [Member]
Debt Instrument [Line Items]
Total debt and other obligations	$ 1,500,000
Stated interest rate	3.40%