Summary of Other Noninterest Expense (Detail) (USD $) In Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Other Noninterest Expense [Line Items]
Telephone	$ 1,416	$ 1,090	$ 2,766	$ 2,230
Data processing services	1,429	925	2,492	1,902
Tax credit fund amortization	1,101	1,005	2,154	2,057
Client services	1,037	767	1,839	1,355
Postage and supplies	562	603	1,084	1,074
Dues and publications	327	444	701	649
Net gain from note repurchases and termination of corresponding interest rate swaps	(3,123)		(3,123)
Other	2,287	1,721	4,986	3,688
Total other noninterest expense	$ 5,036	$ 6,555	$ 12,899	$ 12,955