Other Noninterest Income - Components of Other Income (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Income Statement [Abstract]
Income from bank owned life insurance	$ 2,809	$ 2,787	$ 6,108	$ 5,678
Credit related fees	1,533	1,596	2,974	3,585
Income from derivatives	1,408	728	2,039	1,636
Safety deposit box income	462	488	1,013	1,022
Gain on sale of assets	162	837	476	918
Other miscellaneous	2,281	3,105	4,513	8,492
Total other noninterest income	$ 8,655	$ 9,541	$ 17,123	$ 21,331