Consolidated Statements of Cash Flows - USD ($)	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Operating Activities
Net income	$ 38,670,000	$ 93,072,000
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	72,181,000	21,935,000
Depreciation of premises, furniture, and equipment	8,397,000	8,093,000
Net amortization of premium on securities	10,914,000	6,609,000
Net securities losses	1,005,000	0
Gains on sales of 1-4 family mortgages and corporate loans held-for-sale	(7,230,000)	(3,391,000)
Net losses (gains) on sales and valuation adjustments of OREO	128,000	(1,169,000)
Amortization of the FDIC indemnification asset	892,000	604,000
Net losses on sales and valuation adjustments of premises, furniture, and equipment	213,000	1,252,000
BOLI income	(3,798,000)	(3,645,000)
Share-based compensation expense	7,677,000	6,863,000
Tax benefit related to share-based compensation	148,000	160,000
Amortization of other intangible assets	5,590,000	4,987,000
Originations of mortgage loans held-for-sale	(297,019,000)	(164,398,000)
Proceeds from sales of mortgage loans held-for-sale	292,410,000	154,191,000
Net increase in equity securities	(1,818,000)	(2,918,000)
Net (increase) decrease in accrued interest receivable and other assets	(124,850,000)	19,027,000
Net increase (decrease) in accrued interest payables and other liabilities	12,871,000	(36,151,000)
Net cash provided by operating activities	16,381,000	105,121,000
Investing Activities
Proceeds from maturities, repayments, and calls of securities available-for-sale	497,430,000	167,502,000
Proceeds from sales of securities available-for-sale	39,095,000	93,332,000
Purchases of securities available-for-sale	(914,234,000)	(460,066,000)
Proceeds from maturities, repayments, and calls of securities held-to-maturity	2,467,000	3,162,000
Purchases of securities held-to-maturity	(18,000)	(2,837,000)
Net purchases of FHLB stock	(33,103,000)	(27,683,000)
Net increase in loans	(1,360,147,000)	(394,713,000)
Premiums paid on BOLI, net of proceeds from claims	2,997,000	3,260,000
Proceeds from sales of OREO	230,000	5,236,000
Proceeds from sales of premises, furniture, and equipment	0	2,291,000
Purchases of premises, furniture, and equipment	(4,647,000)	(10,360,000)
Net cash received from (paid for) acquisition	142,282,000	(13,532,000)
Net cash used in investing activities	(1,627,648,000)	(634,408,000)
Financing Activities
Net increase in deposit accounts	1,456,302,000	117,722,000
Net increase in borrowed funds	634,905,000	499,553,000
Net proceeds from the issuance of preferred stock	221,312,000	0
Repurchases of common stock	(22,557,000)	(21,190,000)
Cash dividends paid	(32,480,000)	(25,636,000)
Restricted stock activity	(3,135,000)	(3,770,000)
Net cash provided by financing activities	2,254,347,000	566,679,000
Net increase in cash and cash equivalents	643,080,000	37,392,000
Cash and cash equivalents at beginning of period	299,221,000	289,258,000
Cash and cash equivalents at end of period	942,301,000	326,650,000
Supplemental Disclosures of Cash Flow Information:
Income taxes paid	587,000	16,948,000
Interest paid to depositors and creditors	46,331,000	47,750,000
Dividends declared, but unpaid	15,857,000	15,377,000
Stock issued for acquisitions, net of issuance costs	71,883,000	101,496,000
Non-cash transfers of loans to OREO	121,000	322,000
Non-cash transfers of loans to other assets	0	13,175,000
Non-cash transfers of loans held-for-investment to loans held-for-sale	2,193,000	4,762,000
Non-cash recognition of right-of-use asset/liability	$ 0	$ 143,561,000