Goodwill and Other Intangible Assets - Other Intangible Assets (Detail) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	$ 122,896	$ 138,593
Accumulated Amortization	(78,347)	(92,209)
Valuation Allowance	(849)	(900)
Net Intangible Assets	43,700	45,484
Loan Servicing Rights
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	75,413	73,002
Accumulated Amortization	(54,253)	(52,634)
Valuation Allowance	(849)	(900)
Net Intangible Assets	20,311	19,468
Core Deposits
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	43,396	61,504
Accumulated Amortization	(21,941)	(37,562)
Valuation Allowance	0	0
Net Intangible Assets	21,455	23,942
Other
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	4,087	4,087
Accumulated Amortization	(2,153)	(2,013)
Valuation Allowance	0	0
Net Intangible Assets	$ 1,934	$ 2,074