Consolidated statements of cash flows - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Cash flows from operating activities:
Net income	$ 23,966,000	$ 21,377,000	$ 62,242,000	$ 63,196,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation expense	1,380,000	1,013,000	3,830,000	3,251,000
Amortization of core deposit and other intangibles	1,197,000	777,000	3,180,000	2,432,000
Capitalization of mortgage servicing rights			(30,319,000)	(41,555,000)
Net change in fair value of mortgage servicing rights	10,611,000	1,872,000	23,832,000	(1,656,000)
Stock-based compensation expense			5,621,000	5,327,000
Provision for loan losses	1,831,000	1,818,000	4,103,000	3,198,000
Provision for mortgage loan repurchases	107,000	206,000	255,000	598,000
Accretion of yield on purchased loans			(6,030,000)	(5,745,000)
Accretion of discounts and amortization of premiums on securities, net			2,113,000	2,108,000
(Gain) loss from securities, net	20,000	27,000	(75,000)	116,000
Originations of loans held for sale			(3,477,658,000)	(4,777,814,000)
Repurchases of loans held for sale			(9,919,000)	(7,892,000)
Proceeds from sale of loans held for sale			3,527,632,000	5,003,669,000
Gain on sale and change in fair value of loans held for sale			(72,749,000)	(71,883,000)
Net (gain) loss or write-downs of other real estate owned	126,000	(120,000)	(112,000)	43,000
Gain on other assets	(44,000)	(326,000)	(52,000)	(239,000)
Impairment of goodwill			100,000	0
Provision for deferred income taxes	(1,449,000)	(6,665,000)	(5,900,000)	4,416,000
Changes in:
Other assets and interest receivable			(50,509,000)	(28,473,000)
Accrued expenses and other liabilities			4,243,000	(12,350,000)
Net cash (used in) provided by operating activities			(16,172,000)	140,747,000
Activity in available-for-sale securities:
Sales	22,740,000	0	24,498,000	221,000
Maturities, prepayments and calls	28,694,000	20,068,000	78,861,000	54,576,000
Purchases			(92,059,000)	(137,891,000)
Purchases of FHLB stock			(2,544,000)	(2,020,000)
Net increase in loans			(295,791,000)	(352,776,000)
Proceeds from sale of mortgage servicing rights			29,160,000	39,428,000
Purchases of premises and equipment			(4,052,000)	(8,608,000)
Proceeds from the sale of premises and equipment			1,275,000	341,000
Proceeds from the sale of other real estate owned	854,000	1,457,000	2,718,000	3,666,000
Proceeds from the sale of other assets			0	869,000
Net cash received in business combination			171,032,000	0
Net cash used in investing activities			(86,902,000)	(402,194,000)
Cash flows from financing activities:
Net increase in demand deposits			231,763,000	100,724,000
Net (decrease) increase in time deposits			(70,594,000)	364,354,000
Net increase in securities sold under agreements to repurchase and federal funds purchased			1,546,000	35,824,000
Net increase (decrease) in FHLB advances			68,235,000	(172,451,000)
Share based compensation witholding payment			(3,552,000)	(2,637,000)
Net proceeds from sale of common stock			804,000	1,196,000
Dividends paid			(7,487,000)	(3,684,000)
Net cash provided by financing activities			220,715,000	323,326,000
Net change in cash and cash equivalents			117,641,000	61,879,000
Cash and cash equivalents at beginning of the period			125,356,000	119,751,000
Cash and cash equivalents at end of the period	242,997,000	181,630,000	242,997,000	181,630,000
Supplemental cash flow information:
Interest paid			41,463,000	21,690,000
Taxes paid			21,377,000	19,137,000
Supplemental noncash disclosures:
Transfers from loans to other real estate owned	1,535,000	476,000	3,565,000	1,490,000
Transfers from premises and equipment to other real estate owned at fair value	0	0	2,640,000	0
Loans provided for sales of other real estate owned	0	191,000	166,000	636,000
Transfers from loans to loans held for sale			5,460,000	0
Transfers from loans held for sale to loans			11,476,000	13,584,000
Trade date payable - securities			3,671,000	7,253,000
Dividends declared not paid on restricted stock units	$ 168,000	$ 134,000	168,000	134,000
Decrease to retained earnings for adoption of new accounting standards			1,309,000	109,000
Right-of-use assets obtained in exchange for operating lease liabilities			39,011,000	0
GNMA
Supplemental noncash disclosures:
Derecognition of rebooked GNMA delinquent loans			$ 0	$ 43,035,000