Derivative Financial Instruments - Schedule of Derivatives (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Derivative [Line Items]
Notional Amount	$ 228,686,000		$ 228,686,000		$ 181,119,000
Fair Value Asset	22,000		22,000		260,000
Fair Value Liability	(1,585,000)		(1,585,000)		(11,000)
Changes in fair value of derivatives			(238,000)	$ (123,000)
Total Changes in fair value of derivatives	(1,077,000)	$ 46,000	(1,812,000)	(123,000)
Unrealized cash flow hedge gains (losses) [Member]
Derivative [Line Items]
Changes in fair value of derivatives	(1,026,000)		(1,574,000)
Other Income (Loss) [Member]
Derivative [Line Items]
Changes in fair value of derivatives	(51,000)	46,000	(238,000)	(123,000)
Interest Rate Swaps [Member]
Derivative [Line Items]
Notional Amount	57,140,000		57,140,000		685,000
Fair Value Liability	(1,585,000)		(1,585,000)		(11,000)
Changes in fair value of derivatives	(1,026,000)	4,000	(1,574,000)	5,000
Interest Rate Caps [Member]
Derivative [Line Items]
Notional Amount	171,546,000		171,546,000		180,434,000
Fair Value Asset	22,000		22,000		$ 260,000
Changes in fair value of derivatives	$ (51,000)	$ 42,000	$ (238,000)	$ (128,000)