Derivative Instruments and Hedging Activities - Schedule of Pre-tax Effect of Derivative Financial Instruments on Unaudited Condensed Consolidated Statements of Comprehensive Loss (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Derivatives in Cash Flow Hedging Relationships:
(Loss) gain related to effective portion of derivatives recognized in accumulated other comprehensive loss	$ (1,953)	$ 12,116
Loss related to effective portion of derivatives reclassified from accumulated other comprehensive loss to interest expense	$ (855)	$ (1,851)