Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash flows from operating activities:
Net income	$ 29,380	$ 31,581
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation expense	3,090	2,994
Amortization of core deposit intangibles	1,073	1,605
Capitalization of mortgage servicing rights	(45,624)	(30,890)
Amortization of mortgage servicing rights		6,221
Change in fair value of mortgage servicing rights	3,724
Impairment of mortgage servicing rights		8,089
Stock-based compensation expense	4,808	3,373
Provision for loan losses	(1,906)	(727)
Provision for mortgage loan repurchases	794	1,173
Accretion of yield on purchased loans	(3,545)	(3,195)
Accretion of discounts and amortization of premiums on securities, net	1,948	1,471
Gain from securities, net	(284)	(4,407)
Originations of loans held for sale	(4,612,745)	(3,121,252)
Proceeds from sale of loans held for sale	4,711,364	2,987,252
Gain on sale and change in fair value of loans held for sale	(80,929)	(85,154)
Gain on sale of mortgage servicing rights	(17)
Net gain or write-downs of other real estate owned	(846)	(1,504)
Gain (loss) on other assets	350	(24)
Provision for deferred income taxes	8,226	14,239
Changes in:
Other assets and interest receivable	4,912	(47,046)
Accrued expenses and other liabilities	19,210	10,504
Net cash provided by (used in) operating activities	42,983	(225,697)
Activity in available-for-sale securities:
Sales	94,743	270,663
Maturities, prepayments and calls	63,167	78,661
Purchases	(57,441)	(244,221)
Net increase in loans	(191,033)	(85,209)
Proceeds from sale of mortgage servicing rights	11,952
Purchases of premises and equipment	(2,898)	(3,683)
Proceeds from the sale of premises and equipment	39
Proceeds from the sale of other real estate owned	4,082	6,558
Net cash paid in business combination	(135,141)
Net cash (used in) provided by investing activities	(212,530)	22,769
Cash flows from financing activities:
Net increase in demand and savings deposits	90,247	128,133
Net (decrease) increase in time deposits	(22,789)	73,465
Net decrease in securities sold under agreements to repurchase	(7,005)	(75,996)
(Decrease) increase in short-term borrowings	(113,467)	62,000
Increase (decrease) in long-term debt	30,043	(11,325)
Net proceeds from sale of common stock	153,356	115,525
Dividends paid		(69,300)
Net cash provided by financing activities	130,385	222,502
Net change in cash and cash equivalents	(39,162)	19,574
Cash and cash equivalents at beginning of the period	136,327	97,723
Cash and cash equivalents at end of the period	97,165	117,297
Supplemental cash flow information:
Interest paid	9,652	7,041
Taxes paid	21,130	1,307
Supplemental noncash disclosures:
Transfers from loans to other real estate owned	2,958	2,636
Transfers from other real estate owned to loans	201	259
Transfers from loans held for sale to loans	9,808	5,749
Rebooked GNMA loans under optional repurchase program	13,575
Stock consideration paid in business combination	52,284
Conversion of cash-settled to stock settled compensation		5,388
Trade date receivable - securities		$ 32,648
Fair value election of mortgage servicing rights	$ 1,011