Derivative Financial Instruments - Interest Rate Derivatives Designated and Non Designated (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Derivative [Line Items]
Unrealized (Loss) Gain on Hedge in Other Comprehensive Income	$ (150)	$ (16)	$ (20)	$ (73)
Cash Flow Hedging [Member] | Interest Rate Caps [Member] | 0.5% Strike Rate Derivatives [Member]
Derivative [Line Items]
Derivative Maturity Period			Aug 2014	Aug 2014
Strike Rate	0.50%	0.50%	0.50%	0.50%
Notional Amount of Hedge	13,197	13,478	13,197	13,478
Cost of Hedge			22	22
Estimated Fair Value			1
Unrealized (Loss) Gain on Hedge in Other Comprehensive Income
Change in Hedge Valuations Included in Other Comprehensive Income	(3)		(4)
Cash Flow Hedging [Member] | Interest Rate Cap One [Member] | 0.5% Strike Rate Derivatives [Member]
Derivative [Line Items]
Derivative Maturity Period			May 2016	Oct 2014
Strike Rate	0.50%	1.00%	0.50%	1.00%
Notional Amount of Hedge	42,922	21,000	42,922	21,000
Cost of Hedge				174
Estimated Fair Value			(15)	(165)
Unrealized (Loss) Gain on Hedge in Other Comprehensive Income			(15)
Change in Hedge Valuations Included in Other Comprehensive Income	(147)	(17)	(15)	(77)
Not Designated as Hedging Instrument [Member] | Interest Rate Caps [Member] | 1.25% Strike Rate Derivatives [Member]
Derivative [Line Items]
Derivative Maturity Period			May 2013	May 2013
Strike Rate	1.25%	1.25%	1.25%	1.25%
Notional Amount of Hedge		51,982		51,982
Cost of Hedge			196	196
Estimated Fair Value
Change in Cap Valuations Included in Interest Expense				18
Not Designated as Hedging Instrument [Member] | Interest Rate Caps [Member] | 1.75% Strike Rate Derivatives [Member]
Derivative [Line Items]
Derivative Maturity Period			May 2014	May 2014
Strike Rate	1.75%	1.75%	1.75%	1.75%
Notional Amount of Hedge	51,982	51,982	51,982	51,982
Cost of Hedge			434	434
Estimated Fair Value				1
Change in Cap Valuations Included in Interest Expense		5		46
Not Designated as Hedging Instrument [Member] | Interest Rate Caps [Member] | 1.00% Strike Rate Derivatives [Member]
Derivative [Line Items]
Derivative Maturity Period			Oct 2014	Oct 2014
Strike Rate	1.00%	1.00%	1.00%	1.00%
Notional Amount of Hedge	5,753	21,000	5,753	21,000
Cost of Hedge			174	174
Estimated Fair Value				9
Change in Cap Valuations Included in Interest Expense	$ 1		$ 1