Fair Value Measurement - Reconciliation of All Assets Measured at Fair Value on Recurring Basis Using Significant Unobservable Inputs (Level 3) (Detail) (Interest Rate Caps [Member], USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Interest Rate Caps [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance of recurring Level 3 assets at beginning of period	$ 546	$ 436
Included in other income	111	547
Included in other comprehensive income	0	0
Purchases	0	0
Amortization	(389)	(389)
Sales	0	0
Balance of recurring Level 3 assets at end of period	$ 268	$ 594