Derivative Financial Instruments - Schedule of Derivatives (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Derivative [Line Items]
Notional Amount	$ 222,221,000		$ 222,221,000		$ 181,119,000
Fair Value Asset	73,000		73,000		260,000
Fair Value Liability	(559,000)		(559,000)		(11,000)
Changes in fair value of derivatives			(187,000)	$ (169,000)
Total Changes in fair value of derivatives	198,000	$ (262,000)	(735,000)	(169,000)
Unrealized Gain (Loss) on Cash Flow Hedge [Member]
Derivative [Line Items]
Changes in fair value of derivatives	238,000		(548,000)
Other Income (Loss) [Member]
Derivative [Line Items]
Changes in fair value of derivatives	(40,000)	(262,000)	(187,000)	(169,000)
Interest Rate Swaps [Member]
Derivative [Line Items]
Notional Amount	50,675,000		50,675,000		685,000
Fair Value Liability	(559,000)		(559,000)		(11,000)
Changes in fair value of derivatives	239,000	(1,000)	(548,000)	1,000
Interest Rate Caps [Member]
Derivative [Line Items]
Notional Amount	171,546,000		171,546,000		180,434,000
Fair Value Asset	73,000		73,000		$ 260,000
Changes in fair value of derivatives	$ (41,000)	$ (261,000)	$ (187,000)	$ (170,000)