Derivative Financial Instruments - Balance Sheet (Details) - Interest Rate Swap Contracts - Derivatives Designated As Hedging Instruments - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Derivatives, Fair Value [Line Items]
Derivatives, fair value, net	$ (16,852)	$ (45,199)
Prepaid Expenses Deferred Costs And Other Noncurrent Assets Caption [Member]
Derivatives, Fair Value [Line Items]
Derivative assets, fair value	14,137
Current Portion Of Other Long-Term Liabilities
Derivatives, Fair Value [Line Items]
Derivative liabilities, fair value	(16,533)	(23,327)
Other Long-Term Liabilities
Derivatives, Fair Value [Line Items]
Derivative liabilities, fair value	$ (14,456)	$ (21,872)