Derivative Instruments - Effect of Interest Rate Swaps on Consolidated Statements of Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Realized gains (losses) on interest rate swaps	[1]	$ (96,470)	$ (130,762)	$ (200,626)	$ (278,237)
Realized gain (losses) on termination of interest rate swaps		(58)	(60,064)	(58)	(60,064)
Unrealized gains (losses) on interest rate swaps		$ (177,567)	$ (373,220)	$ (28,383)	$ (1,404,940)

[1] Consists of interest expense on interest rate swaps.