Goodwill and Other Intangible Assets - Other Intangible Assets (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	$ 134,253	$ 143,020
Accumulated Amortization	(89,469)	(93,849)
Valuation Allowance	(746)	(289)
Net Intangible Assets	44,038	48,882
Loan Servicing Rights
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	68,662	75,932
Accumulated Amortization	(51,301)	(59,251)
Valuation Allowance	(746)	(289)
Net Intangible Assets	16,615	16,392
Core Deposits
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	61,504	62,714
Accumulated Amortization	(36,230)	(31,934)
Valuation Allowance	0	0
Net Intangible Assets	25,274	30,780
Other
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	4,087	4,374
Accumulated Amortization	(1,938)	(2,664)
Valuation Allowance	0	0
Net Intangible Assets	$ 2,149	$ 1,710