Goodwill and Other Intangible Assets - Other Intangible Assets (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	$ 121,591	$ 138,593
Accumulated Amortization	(75,734)	(92,209)
Valuation Allowance	(899)	(900)
Net Intangible Assets	44,958	45,484
Loan Servicing Rights
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	74,108	73,002
Accumulated Amortization	(52,954)	(52,634)
Valuation Allowance	(899)	(900)
Net Intangible Assets	20,255	19,468
Core Deposits
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	43,396	61,504
Accumulated Amortization	(20,697)	(37,562)
Valuation Allowance	0	0
Net Intangible Assets	22,699	23,942
Other
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	4,087	4,087
Accumulated Amortization	(2,083)	(2,013)
Valuation Allowance	0	0
Net Intangible Assets	$ 2,004	$ 2,074