Other Noninterest Income and Other Noninterest Expense - Summary of Other Noninterest Expense (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Other Income and Expenses [Abstract]
Client services	$ 2,359	$ 1,935
Data processing services	2,227	1,912
Tax credit fund amortization	2,028	1,317
Telephone	1,748	1,557
Postage and supplies	769	538
Dues and publications	497	458
Other	1,562	2,218
Total other noninterest expense	$ 11,190	$ 9,935