Derivative Instruments and Hedging Activities - Schedule of Changes in Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Accumulated other comprehensive income (loss):
Beginning Balance	$ 287,466	$ 461,215
Ending Balance	265,194	287,466
Accumulated Other Comprehensive (Loss) Income [Member]
Accumulated other comprehensive income (loss):
Beginning Balance	(5,076)	(13,694)
Impact of adoption of ASU 2018-02	(1,094)
Ending Balance	2,284	(5,076)
Gains (Losses) on Cash Flow Hedges [Member]
Accumulated other comprehensive income (loss):
Impact of adoption of ASU 2018-02	(1,094)
Other comprehensive income (loss) before reclassifications	10,426	972
Amounts reclassified from accumulated other comprehensive income (loss) to interest expense	(1,972)	7,646
Unrealized gain on derivatives, net of tax	$ 8,454	$ 8,618