Derivative Financial Instruments - Interest Rate Derivatives Designated and Non Designated (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014
Cash Flow Hedging [Member] | Interest Rate Caps and Swaps [Member] | 0.5% Strike Rate Derivatives [Member]
Derivative [Line Items]
Derivative Maturity Period	2014-08
Strike Rate	0.50%
Notional Amount of Hedge	$ 13,052
Cost of Hedge	22
Estimated Fair Value
Change in Hedge Valuations Included in Other Comprehensive Income	2
Cash Flow Hedging [Member] | Interest Rate Caps and Swaps [Member] | 0.69% Strike Rate Derivatives [Member]
Derivative [Line Items]
Derivative Maturity Period	2016-10
Strike Rate	0.69%
Notional Amount of Hedge	150,000
Cost of Hedge
Estimated Fair Value	(141)
Change in Hedge Valuations Included in Other Comprehensive Income	(55)
Cash Flow Hedging [Member] | Interest Rate Caps and Swaps [Member] | 4.00% Strike Rate Derivatives [Member]
Derivative [Line Items]
Derivative Maturity Period	2017-11
Strike Rate	4.00%
Notional Amount of Hedge	50,000
Cost of Hedge	165
Estimated Fair Value	172
Change in Hedge Valuations Included in Other Comprehensive Income	(38)
Cash Flow Hedging [Member] | Interest Rate Caps and Swaps [Member] | 5.00% Strike Rate Derivatives [Member]
Derivative [Line Items]
Derivative Maturity Period	2018-11
Strike Rate	5.00%
Notional Amount of Hedge	50,000
Cost of Hedge	220
Estimated Fair Value	186
Change in Hedge Valuations Included in Other Comprehensive Income	(38)
Cash Flow Hedging [Member] | Interest Rate Caps And Swaps [Member] | 0.5% Strike Rate Derivatives [Member]
Derivative [Line Items]
Derivative Maturity Period	2016-05
Strike Rate	0.50%
Notional Amount of Hedge	42,193
Cost of Hedge
Estimated Fair Value	(48)
Change in Hedge Valuations Included in Other Comprehensive Income	(16)
Not Designated as Hedging Instrument [Member] | Interest Rate Caps and Swaps [Member] | 1.75% Strike Rate Derivatives [Member]
Derivative [Line Items]
Derivative Maturity Period	2014-05
Strike Rate	1.75%
Notional Amount of Hedge	51,982
Cost of Hedge	434
Estimated Fair Value
Change in Hedge Valuations Included in Interest Expense
Not Designated as Hedging Instrument [Member] | Interest Rate Caps and Swaps [Member] | 1.00% Strike Rate Derivatives [Member]
Derivative [Line Items]
Derivative Maturity Period	2014-10
Strike Rate	1.00%
Notional Amount of Hedge	5,753
Cost of Hedge	174
Estimated Fair Value
Change in Hedge Valuations Included in Interest Expense
Not Designated as Hedging Instrument [Member] | Interest Rate Caps and Swaps [Member] | 3.00% Strike Rate Derivatives [Member]
Derivative [Line Items]
Derivative Maturity Period	2015-08
Strike Rate	3.00%
Notional Amount of Hedge	25,500
Cost of Hedge	10
Estimated Fair Value	10
Change in Hedge Valuations Included in Interest Expense