Derivatives and Hedging Activities - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014 Derivative	Jun. 30, 2013	Jun. 30, 2014 Derivative	Jun. 30, 2013
Derivative [Line Items]
Net loss in interest expense related to hedge ineffectiveness	$ (8,000)		$ (18,000)
Termination value of derivatives in net liability position	800,000		800,000
Interest Rate Swap [Member] | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Notional amount of interest rate swaps	6,800,000		6,800,000
Number of interest rate swaps	1		1
Interest Rate Swap [Member] | Derivatives not Designated as Hedging Instruments [Member]
Derivative [Line Items]
Notional amount of interest rate swaps	343,500,000		343,500,000
Number of interest rate swaps	26		26
Gain (loss) related to changes in fair value of swaps	$ 31,000	$ 48,000	$ (52,000)	$ 154,000