Interest Rate Swaps - Impact of Interest Rate Swaps on Consolidated Statements of Operations - (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Derivative [Line Items]
Amount of loss reclassified from AOCI into earnings under “Interest expense” (effective portion)	$ (280)	$ (577)	$ (1,090)	$ (1,671)
Amount of gain (loss) recognized in earnings under “Interest expense” (ineffective portion and amount excluded from effectiveness testing)	0	0	0	0
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent
Derivative [Line Items]
Amount of gain (loss) recognized in AOCI on derivatives (effective portion)	$ 382	$ 1,036	$ (672)	$ (4,465)