Derivative Instruments and Hedging Activities - Schedule of Changes in Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Accumulated other comprehensive loss:
Balance at December 31, 2014			$ (483)
Unrealized loss on derivatives, net of tax	$ (10,740)	$ 1,087	(15,360)	$ 7
Balance at September 30, 2015	(15,843)		(15,843)
(Losses) Gains on Cash Flow Hedges [Member]
Accumulated other comprehensive loss:
Balance at December 31, 2014			(483)
Other comprehensive loss before reclassifications			(16,830)
Amounts reclassified from accumulated other comprehensive loss to interest expense			1,470
Unrealized loss on derivatives, net of tax			(15,360)
Balance at September 30, 2015	$ (15,843)		$ (15,843)