Interest Rate Derivative Instruments - Additional Information (Detail) (USD $)	3 Months Ended	6 Months Ended	3 Months Ended		6 Months Ended				6 Months Ended
	Jun. 30, 2014	Jun. 30, 2014	Jun. 30, 2014 Interest Rate Swap [Member]	Jun. 30, 2013 Interest Rate Swap [Member]	Jun. 30, 2014 Interest Rate Swap [Member]	Jun. 30, 2013 Interest Rate Swap [Member]	Jun. 30, 2014 Interest Rate Swap [Member] Fair Value Measurements, Level 2 [Member]	Dec. 31, 2013 Interest Rate Swap [Member] Fair Value Measurements, Level 2 [Member]	Jun. 30, 2014 Cash Flow Hedging [Member]	Jun. 30, 2013 Cash Flow Hedging [Member]	Jun. 30, 2014 Cash Flow Hedging [Member] Interest Rate Swap [Member]	Feb. 29, 2012 Cash Flow Hedging [Member] Interest Rate Swap [Member]	Feb. 08, 2012 Cash Flow Hedging [Member] Interest Rate Swap [Member]	Jun. 30, 2014 Cash Flow Hedging [Member] Interest Rate Swap [Member] LIBOR [Member]
Derivative [Line Items]
Derivative instruments, notional amount											$ 50,000,000	$ 150,000,000	$ 150,000,000
Capped LIBOR rate														3.00%
Unrealized gains or losses on cash flow hedge derivative effective portion									200,000	200,000
Interest expense related to payments on interest rate swaps	2,208,000	4,273,000	200,000	100,000	300,000	200,000
Interest rate swap liability recorded at fair value							$ 200,000	$ 500,000