Derivatives - Additional Information (Detail) $ in Thousands	1 Months Ended			12 Months Ended
	Sep. 30, 2015 USD ($)	Aug. 31, 2014 USD ($)	Jan. 31, 2014 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Derivative [Line Items]
Mark-to-Market Gain on Interest Rate Protection Agreements				$ (11,546)	$ 0	$ 52
2014 Swaps
Derivative [Line Items]
Swaps, Number of Instruments Held			4
Swaps, Notional Amount			$ 200,000
Swaps, Average Fixed Interest Rate			2.29%
LIBOR rate			one month LIBOR
2015 Swaps
Derivative [Line Items]
Swaps, Number of Instruments Held	6
Swaps, Notional Amount	$ 260,000
Swaps, Average Fixed Interest Rate	1.79%
LIBOR rate	one month LIBOR
Settled Swaps
Derivative [Line Items]
Swaps, Number of Instruments Held		3
Swaps, Notional Amount		$ 220,000
LIBOR rate		three month LIBOR
Derivative, Cost of Hedge				$ 11,546