CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash Flows from Operating Activities
Net income	$ 102,953	$ 98,928	$ 62,726
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	10,406	4,429	5,303
Amortization of intangible assets	9,547	5,854	5,245
Amortization of mortgage servicing rights	2,710	1,531	1,511
Depreciation and amortization of premises and equipment	11,879	9,556	8,615
Net amortization (accretion) of premium (discount) on portfolio loans	(10,905)	(10,452)	(12,205)
Net amortization (accretion) of premium (discount) on investment securities	6,106	8,311	6,665
Net amortization (accretion) of premium (discount) on time deposits	(1,648)	(243)	(392)
Net amortization (accretion) of premium (discount) on FHLB advances and other borrowings	309	146	140
Impairment of OREO	62	18	42
Impairment of fixed assets held for sale	2,026	817	99
Impairment of leases	348	146
Change in fair value of equity securities, net	759	(2,162)
(Gain) loss on sales of securities, net	(733)	1,780	(362)
(Gain) loss on sale of loans, net	(16,819)	(10,446)	(45,443)
(Gain) loss on sale of OREO	(102)	(384)	(1,632)
(Gain) loss on sale of premises and equipment	113	162	(327)
Realized (gain) loss on preferred stock and equity securities	(8)	51	(781)
(Gain) loss on life insurance proceeds	(1,604)	(666)	(227)
Provision for deferred income taxes	96	7,116	14,100
Stock-based and non-cash compensation	3,997	3,721	2,752
Decrease in deferred compensation	(6,781)	(3,780)	(757)
Increase in cash surrender value of bank owned life insurance	(4,191)	(3,060)	(2,352)
Mortgage loans originated for sale	(667,515)	(425,322)	(1,487,726)
Proceeds from sales of mortgage loans	641,778	504,721	1,693,632
Net change in operating assets and liabilities:
Decrease in other assets	5,397	9,580	8,925
(Decrease) increase in other liabilities	(7,380)	2,195	(4,193)
Net cash provided by operating activities	80,800	202,547	253,358
Cash Flows from Investing Activities
Purchases of debt securities held to maturity		(217,766)	(352,679)
Purchase of equity securities	(550)
Purchases of debt securities available for sale	(408,941)	(124,234)	(141,685)
Purchase of FHLB stock	(3,700)
Proceeds from sales of equity securities	1,474	920
Proceeds from sales of debt securities available for sale	227,371	122,584	139,765
Proceeds from paydowns and maturities of debt securities held to maturity	14,422	50,560	11,268
Proceeds from paydowns and maturities of debt securities available for sale	541,753	163,582	193,294
Proceeds from the redemption of FHLB stock	5,369	4,864	6,090
Net cash (received) paid in acquisitions	(61,481)		26,979
Net change in loans	(244,333)	(49,864)	(169,150)
Cash paid for premiums on bank-owned life insurance	(6)
Purchases of premises and equipment	(13,238)	(11,618)	(14,980)
Proceeds from life insurance	3,915
Proceeds from disposition of premises and equipment	424	324	2,224
Capitalized expenditures on OREO	(2)
Proceeds from sale of OREO	2,481	5,298	5,024
Net cash provided by (used in) investing activities	64,958	(55,350)	(293,850)
Cash Flows from Financing Activities
Net change in deposits	215,519	123,600	111,788
Net change in federal funds purchased and securities sold under agreements to repurchase	(30,904)	(118,770)	28,898
Proceeds from other borrowings	60,000		98,312
Repayment of other borrowings	(6,000)	(5,500)	(9,800)
Net change in short-term FHLB advances	(23,443)	(220,000)	60,300
Repayments of long-term FHLB advances	(1,224)		(30,000)
Cash dividends paid	(45,171)	(39,010)	(30,707)
Purchase of treasury stock	(24,292)
Cash paid for withholding taxes on share-based payments	(863)	(1,208)	(2,274)
Proceeds from stock options exercised	169	392	906
Common stock issuance costs	(234)		(365)
Net cash provided by (used in) financing activities	143,557	(260,496)	227,058
Net increase (decrease) in cash and cash equivalents	289,315	(113,299)	186,566
Cash and cash equivalents, beginning of period	239,973	353,272	166,706
Cash and cash equivalents, ending of period	529,288	239,973	353,272
Cash Payments for:
Interest	70,577	40,639	19,342
Income taxes	24,725	23,183	26,419
Non-cash Investing and Financing Activities:
OREO acquired in settlement of loans	4,872	4,025	$ 1,417
Other assets transferred to equity investments		$ 4,000
Transfer of debt securities held to maturity to available for sale	$ 593,548