Goodwill And Other Intangible Assets (Summary of Finite-Lived Intangible Assets) (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Total other intangible assets, net	$ 23,725	$ 24,209	$ 18,858
Core deposit intangibles | Community banking
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	35,654	34,841	25,881
Accumulated amortization	(18,543)	(17,382)	(14,192)
Net carrying amount	17,111	17,459	11,689
Customer list intangibles | Specialty finance
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	1,800	1,800	1,800
Accumulated amortization	(1,076)	(1,052)	(971)
Net carrying amount	724	748	829
Customer list and other intangibles | Wealth management
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	7,940	7,940	7,940
Accumulated amortization	(2,050)	(1,938)	(1,600)
Net carrying amount	$ 5,890	$ 6,002	$ 6,340