Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Operating Activities
Net income	$ 19,322	$ 39,905
Adjustments reconciling net income to net cash provided by (used in) operating activities:
Depreciation	3,916	2,623
Net losses on sale or disposal of premises and equipment including write-downs	125	348
Net write-downs on other assets	417	571
Provision for credit losses	41,047	3,408
Net losses on sale of other real estate owned including write-downs	885	9
Share-based compensation expense	559	1,152
Amortization of intangible assets	5,631	3,132
Amortization of operating lease right-of-use assets	3,400	1,547
Provision for deferred taxes	(7,333)	2,963
Net amortization of investment securities available for sale	1,385	819
Net (gain) loss on securities	9	(66)
Accretion of discount on purchased loans, net	(6,320)	(2,632)
Accretion on other borrowings	46	18
Accretion on subordinated deferrable interest debentures	485	342
Loan servicing asset impairment	22,165	0
Originations of mortgage loans held for sale	(1,252,379)	(296,197)
Payments received on mortgage loans held for sale	14,957	194
Proceeds from sales of mortgage loans held for sale	1,530,122	305,473
Net gains on sale of mortgage loans held for sale	(40,809)	(11,484)
Originations of SBA loans	(11,647)	(9,515)
Proceeds from sales of SBA loans	20,062	11,870
Net gains on sale of SBA loans	(1,824)	(1,113)
Increase in cash surrender value of bank owned life insurance	(969)	(501)
Changes in FDIC loss-share payable, net of cash payments	(1,506)	1,141
Change attributable to other operating activities	(40,757)	5,670
Net cash provided by operating activities	300,989	59,677
Investing Activities, net of effects of business combinations
Proceeds from maturities of time deposits in other banks	0	3,441
Purchases of securities available for sale	0	(146,874)
Proceeds from prepayments and maturities of securities available for sale	76,386	43,942
Proceeds from sales of securities available for sale	0	64,995
Net (increase) decrease in other investments	(14,844)	(694)
Net (increase) decrease in loans	(264,063)	24,041
Purchases of premises and equipment	(3,572)	(1,550)
Proceeds from sales of premises and equipment	0	275
Proceeds from sales of other real estate owned	1,284	2,610
Payments paid to FDIC under loss-share agreements	(25)	(1,794)
Net cash and cash equivalents received in acquisitions	2	0
Net cash used in investing activities	(204,832)	(11,608)
Financing Activities, net of effects of business combinations
Net (decrease) increase in deposits	(182,455)	151,562
Net decrease in securities sold under agreements to repurchase	(5,475)	(16,125)
Proceeds from other borrowings	2,770,000	0
Repayment of other borrowings	(2,625,084)	(338)
Repayment of subordinated deferrable interest debentures	(5,155)	0
Proceeds from exercise of stock options	701	54
Dividends paid - common stock	(10,426)	(4,751)
Purchase of treasury shares	(7,956)	(998)
Net cash provided by (used in) financing activities	(65,850)	129,404
Net increase in cash and cash equivalents	30,307	177,473
Cash and cash equivalents at beginning of period	621,849	679,527
Cash and cash equivalents at end of period	652,156	857,000
Cash paid (received) during the period for:
Interest	35,234	25,741
Income taxes	(77)	49
Loans transferred to other real estate owned	3,674	2,787
Loans provided for the sales of other real estate owned	299	75
Initial recognition of operating lease right-of-use assets	0	27,286
Initial recognition of operating lease liabilities	0	29,651
Right-of-use assets obtained in exchange for new operating lease liabilities	2,889	0
Assets acquired in business acquisitions	0	1,335
Liabilities assumed in business acquisitions	0	(792)
Change in unrealized gain (loss) on securities available for sale, net of tax	21,653	3,821
Change in unrealized gain (loss) on cash flow hedge, net of tax	$ (97)	$ (173)