Fair Value Measurement - Reconciliation of All Assets Measured at Fair Value on Recurring Basis Using Significant Unobservable Inputs (Level 3) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
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	$ 180	$ 546
Included in other income	75	2
Amortization	(129)	(129)
Balance of recurring Level 3 assets at end of period	126	419
Loans Held For Sale, at Fair Value [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Included in mortgage banking income	561
Originations	1,047
Balance of recurring Level 3 assets at end of period	$ 1,608