Derivative Instruments and Hedging Activities - Derivatives Designated as Hedging Instruments (Detail) - Designated as Hedging Instrument [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Notional Amount	$ 19,610		$ 19,610		$ 19,945
Derivative Assets, Fair Value	0		0		0
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	202		202		241
Net loss	(95)	$ 0	(191)	$ 0
Amounts included in accumulated other comprehensive income (loss)	(131)	(157)
Interest Rate Swap [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Notional Amount	19,610		19,610		19,945
Derivative Assets, Fair Value	0		0		0
Amounts included in accumulated other comprehensive income (loss)	(131)	(157)
Interest Rate Swap [Member] | Cash Flow Hedging [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate swap—cash flow hedge—interest payments	95	$ 0	191	$ 0
Interest Rate Swap [Member] | Cash Flow Hedging [Member] | Other Liabilities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	$ 202		$ 202		$ 241