Consolidated Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating Activities
Net income	$ 81,698	$ 124,962
Adjustments reconciling net income to net cash provided by (used in) operating activities:
Depreciation	4,553	4,080
Net (gains) losses on sale or disposal of premises and equipment	37	139
Net write-downs on other assets	0	122
Provision for credit losses	6,231	(28,591)
Net write-downs and (gains) losses on sale of other real estate owned	(1,459)	(560)
Share-based compensation expense	1,499	1,753
Amortization of intangible assets	5,181	4,126
Amortization of operating lease right of use assets	2,904	2,979
Provision for deferred taxes	6,435	12,919
Net amortization of investment securities available-for-sale	392	1,121
Net amortization of investment securities held-to-maturity	26	0
Net amortization of other investments	252	0
Net loss on securities	27	12
Accretion of discount on purchased loans, net	(1,006)	(6,127)
Net amortization on other borrowings	108	112
Amortization of subordinated deferrable interest debentures	499	488
Loan servicing asset impairment (recovery)	(9,654)	(10,639)
Originations of mortgage loans held for sale	(1,220,771)	(2,340,847)
Payments received on mortgage loans held for sale	10,505	10,680
Proceeds from sales of mortgage loans held for sale	1,464,735	1,816,503
Net (gains) losses on sale of mortgage loans held for sale	22,792	(41,720)
Originations of SBA loans	(14,042)	(11,976)
Proceeds from sales of SBA loans	20,461	12,518
Net gains on sale of SBA loans	(2,325)	(1,192)
Increase in cash surrender value of bank owned life insurance	(1,768)	(814)
Gain on bank owned life insurance proceeds	0	(603)
Net gains on other loans held for sale	0	(457)
Change attributable to other operating activities	(16,887)	(13,597)
Net cash provided by (used in) operating activities	360,423	(464,609)
Investing Activities, net of effects of business combinations
Purchases of securities available-for-sale	(15,667)	0
Purchases of investment securities held-to-maturity	(12,036)	0
Proceeds from maturities and paydowns of securities available-for-sale	42,844	112,730
Proceeds from maturities and paydowns of securities held-to-maturity	406	0
Net (increase) decrease in other investments	(2,122)	570
Net increase in loans	(205,189)	(72,093)
Purchases of premises and equipment	(3,550)	(13,809)
Proceeds from sale of premises and equipment	0	930
Proceeds from sales of other real estate owned	3,524	4,048
Proceeds from bank owned life insurance	0	1,309
Payments received on other loans held for sale	0	9,136
Proceeds from sales of other loans held for sale	0	156,803
Net cash and cash equivalents paid in acquisitions	(13,237)	0
Net cash provided by (used in) investing activities	(205,027)	199,624
Financing Activities, net of effects of business combinations
Net increase (decrease) in deposits	(77,112)	918,050
Net decrease in securities sold under agreements to repurchase	(3,780)	(2,321)
Repayment of other borrowings	(314,467)	(36)
Proceeds from exercise of stock options	1,445	3,002
Dividends paid - common stock	(10,445)	(10,432)
Purchase of treasury shares	(17,234)	(1,456)
Net cash provided by (used in) financing activities	(421,593)	906,807
Net increase (decrease) in cash, cash equivalents and restricted cash	(266,197)	641,822
Cash, cash equivalents and restricted cash at beginning of period	4,064,657	2,117,306
Cash, cash equivalents and restricted cash at end of period	3,798,460	2,759,128
Cash paid during the period for:
Interest	9,022	11,335
Income taxes	204	(1)
Loans transferred to other real estate owned	165	449
Loans transferred from loans held for sale to loans held for investment	71,727	48,313
Right-of-use assets obtained in exchange for new operating lease liabilities	1,537	0
Assets acquired in business acquisitions	10,023	0
Liabilities assumed in business acquisitions	(3,214)	0
Change in unrealized gain (loss) on securities available-for-sale, net of tax	(17,431)	(7,415)
Security purchases settled in a subsequent period	$ (36,216)	$ 0