Other Noninterest Expense - Components of Other Noninterest Expense (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Income Statement [Abstract]
Advertising	$ 1,759	$ 2,177
Ad valorem and franchise taxes	2,661	2,202
Printing and supplies	1,329	1,309
Insurance expense	1,040	1,066
Travel expense	896	1,113
Entertainment and contributions	1,412	1,722
Tax credit investment amortization	2,172	1,426
Other miscellaneous	4,548	7,616
Total other noninterest expense	$ 15,817	$ 18,631