Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating Activities
Net income	$ 346,540	$ 376,913	$ 261,988
Adjustments to reconcile net income to net cash used in operating activities:
Depreciation	18,416	17,225	15,759
Net losses on sale or disposal of premises and equipment	156	2,882	777
Net write-downs on other assets	0	260	1,715
Provision for credit losses	71,697	(35,365)	145,380
Net write-downs and (gains) losses on sale of other real estate owned	(1,773)	538	1,049
Share-based compensation expense	6,706	7,948	3,810
Amortization of intangible assets	19,744	14,965	19,612
Amortization of operating lease right of use assets	12,639	15,739	19,740
Provision for deferred taxes	(35,677)	38,411	(7,929)
Net amortization of debt securities available-for-sale	(644)	2,786	6,153
Net amortization of debt securities held-to-maturity	37	40	0
Net amortization of other investments	722	62	0
Net gain on securities	(203)	(515)	(5)
Accretion of discount on purchased loans, net	285	(16,349)	(27,351)
Net amortization on other borrowings	433	438	256
Amortization of subordinated deferrable interest debentures	1,994	1,983	1,940
Loan servicing asset impairment (recovery)	(21,824)	(14,530)	40,067
Originations of mortgage loans held for sale	(3,949,676)	(7,780,436)	(9,067,706)
Payments received on mortgage loans held for sale	23,324	53,313	43,663
Proceeds from sales of mortgage loans held for sale	4,493,742	7,459,163	9,864,464
Net (gains) losses on mortgage loans held for sale	93,133	(152,422)	(387,124)
Originations of SBA loans	(46,479)	(67,865)	(97,017)
Proceeds from sales of SBA loans	57,171	71,610	109,296
Net gains on sales of SBA loans	(5,552)	(6,623)	(7,226)
Increase in cash surrender value of bank owned life insurance	(7,305)	(5,385)	(3,630)
Gain on bank owned life insurance proceeds	(55)	(603)	(948)
Gains on sale of other loans held for sale	0	(457)	0
Loss on sale of loans	0	0	386
Gain on sale of mortgage servicing rights	(1,356)	0	0
Changes in FDIC loss-share receivable/payable, net of cash payments received	0	0	997
(Increase) decrease in interest receivable	(20,125)	19,337	(23,892)
Increase (decrease) in interest payable	6,217	(1,175)	(6,036)
Increase (decrease) in taxes payable	5,177	7,005	(12,062)
Change attributable to other operating activities	(4,991)	247	(97,730)
Net cash provided by operating activities	1,062,473	9,140	798,396
Investing Activities, net of effects of business combinations
Proceeds from maturities of time deposits in other banks	0	249	0
Purchases of securities available-for-sale	(1,172,323)	0	0
Purchases of securities held-to-maturity	(57,408)	(80,355)	0
Proceeds from prepayments and maturities of securities available-for-sale	186,849	364,907	435,204
Proceeds from prepayments and maturities of securities held-to-maturity	2,357	465	0
Net (increase) decrease in other investments	(63,959)	(18,897)	37,222
Net increase in loans	(3,345,287)	(566,237)	(1,733,057)
Payments received on other loans held for sale	0	9,136	12,954
Purchase of loan pool	(472,266)	0	0
Proceeds from sale of mortgage servicing rights	119,845	0	0
Purchases of premises and equipment	(13,568)	(25,448)	(18,116)
Proceeds from sale of premises and equipment	46	1,958	718
Proceeds from sales of other real estate owned	5,086	11,790	14,059
Purchase of bank owned life insurance	(50,000)	(150,000)	0
Payments paid to FDIC under loss-sharing agreements	0	0	(20,639)
Proceeds from bank owned life insurance	101	1,309	3,381
Proceeds from sales of other loans held for sale	0	156,803	0
Proceeds from sales of loans	0	0	69,965
Net cash proceeds received from (paid in) acquisitions	(14,003)	(126,664)	(2,417)
Net cash used in investing activities	(4,874,530)	(420,984)	(1,200,726)
Financing Activities, net of effects of business combinations
Net increase (decrease) in deposits	(202,815)	2,708,021	2,932,864
Net decrease in securities sold under agreements to repurchase	(5,845)	(5,796)	(8,994)
Proceeds from other borrowings	3,950,000	0	7,202,981
Repayment of other borrowings	(2,814,576)	(296,325)	(8,176,491)
Repayment of subordinated deferrable interest debentures	0	0	(5,155)
Proceeds from exercise of stock options	2,799	4,532	2,262
Dividends paid - common stock	(41,610)	(41,798)	(41,685)
Purchase of treasury shares	(22,421)	(9,439)	(7,995)
Net cash provided by financing activities	865,532	2,359,195	1,897,787
Net increase (decrease) in cash, cash equivalents and restricted cash	(2,946,525)	1,947,351	1,495,457
Cash, cash equivalents and restricted cash at beginning of period	4,064,657	2,117,306	621,849
Cash, cash equivalents and restricted cash at end of period	1,118,132	4,064,657	2,117,306
Cash paid during the year for:
Interest	86,643	48,960	94,786
Income taxes	133,894	71,807	98,609
Loans transferred to other real estate owned	346	4,258	7,398
Loans transferred from loans held for sale to loans held for investment	196,891	170,435	196,804
Loans transferred from loans held for investment to loans held for sale	0	0	179,407
Loans provided for the sales of other real estate owned	2,288	1,052	767
Right-of-use assets obtained in exchange for new operating lease liabilities	7,226	12,792	54,107
Assets acquired in business combination	3,216	886,553	0
Liabilities assumed in business combination	(10,787)	690,116	0
Change in unrealized gain (loss) on securities available-for-sale, net of tax	(62,097)	(17,915)	15,363
Change in unrealized gain on cash flow hedge, net of tax	$ 0	$ 0	$ 147