Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Cash flows from operating activities:
Net income	$ 20,992	$ 30,374
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation expense	1,993	2,022
Amortization of core deposit intangibles	515	1,079
Capitalization of mortgage servicing rights	(29,659)	(19,783)
Amortization of mortgage servicing rights		3,425
Change in fair value of mortgage servicing rights	2,341
Impairment of mortgage servicing rights		5,687
Stock-based compensation expense	3,154
Provision for loan losses	(1,122)	(798)
Provision for mortgage loan repurchases	384	703
Accretion of yield on purchased loans	(848)	(2,381)
Accretion of discounts and amortization of premiums on securities, net	1,290	761
Gain on sales of securities	(30)	(3,991)
Origination of loans held for sale	(2,944,481)	(1,762,143)
Proceeds from sale of loans held for sale	3,071,027	1,759,546
Gain on sale and change in fair value of loans held for sale	(52,165)	(49,985)
Gain on sale of mortgage servicing rights	(17)
Net (gain) loss on sales or write-downs of foreclosed assets	(771)	142
Gain on other assets	(39)	(17)
Provision for deferred income taxes	7,952	1,046
Changes in:
Other assets and interest receivable	6,303	(22,018)
Accrued expenses and other liabilities	(19,410)	7,837
Net cash provided by (used in) operating activities	67,409	(48,494)
Activity in available-for-sale securities:
Sales	12,158	268,995
Maturities, prepayments and calls	41,851	44,172
Purchases	(22,885)	(202,762)
Net increase in loans	(114,201)	(43,551)
Proceeds from sale of mortgage servicing rights	11,952
Purchases of premises and equipment	(1,734)	(2,515)
Proceeds from the sale of premises and equipment	39
Proceeds from the sale of foreclosed assets	2,930	3,514
Net cash (used in) provided by investing activities	(69,890)	67,853
Cash flows from financing activities:
Net increase in demand and savings deposits	50,461	1,800
Net increase in time deposits	5,570	74,023
Net decrease in securities sold under agreements to repurchase	(5,218)	(75,855)
Decrease in short-term borrowings	(150,000)	(18,000)
Payments on long-term debt	(1,102)	(831)
Net proceeds from sale of common stock	152,721
Dividends paid		(9,300)
Net cash provided by (used in) financing activities	52,432	(28,163)
Net change in cash and cash equivalents	49,951	(8,804)
Cash and cash equivalents at beginning of the period	136,327	97,723
Cash and cash equivalents at end of the period	186,278	88,919
Supplemental cash flow information:
Interest paid	5,608	4,680
Taxes paid	18,122	1,307
Supplemental noncash disclosures:
Transfers from loans to foreclosed real estate	1,162	2,176
Transfers from foreclosed real estate to loans	36	259
Transfers from loans held for sale to loans	5,645	$ 3,529
Fair value election of mortgage servicing rights	$ 1,011