Consolidated Statements of Cash Flows - USD ($)	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Operating Activities
Net income	$ 66,293,000	$ 147,617,000
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	88,108,000	34,433,000
Depreciation of premises, furniture, and equipment	12,540,000	12,182,000
Net amortization of premium on securities	16,203,000	11,897,000
Net securities gains	(13,323,000)	0
Gains on sales of 1-4 family mortgages and corporate loans held-for-sale	(14,091,000)	(6,327,000)
Net losses (gains) on sales and valuation adjustments of OREO	221,000	(2,358,000)
Amortization of the FDIC indemnification asset	892,000	906,000
Net losses on sales and valuation adjustments of premises, furniture, and equipment	9,033,000	1,226,000
BOLI income	(5,503,000)	(5,597,000)
Share-based compensation expense	11,242,000	10,018,000
Tax benefit related to share-based compensation	271,000	311,000
Amortization of other intangible assets	8,400,000	7,737,000
Originations of mortgage loans held-for-sale	(592,196,000)	(335,903,000)
Proceeds from sales of mortgage loans held-for-sale	551,105,000	297,967,000
Net increase in equity securities	(12,885,000)	(2,951,000)
Net (increase) decrease in accrued interest receivable and other assets	(111,925,000)	1,244,000
Net increase (decrease) in accrued interest payables and other liabilities	80,487,000	(22,628,000)
Net cash provided by operating activities	94,872,000	149,774,000
Investing Activities
Proceeds from maturities, repayments, and calls of securities available-for-sale	986,145,000	305,973,000
Proceeds from sales of securities available-for-sale	281,869,000	93,332,000
Purchases of securities available-for-sale	(1,499,176,000)	(703,216,000)
Proceeds from maturities, repayments, and calls of securities held-to-maturity	9,934,000	3,873,000
Purchases of securities held-to-maturity	(10,050,000)	(2,837,000)
Net purchases of FHLB stock	(22,711,000)	(31,062,000)
Net increase in loans	(1,078,458,000)	(655,871,000)
Premiums paid on BOLI, net of proceeds from claims	3,922,000	4,720,000
Proceeds from sales of OREO	3,709,000	9,430,000
Proceeds from sales of premises, furniture, and equipment	1,132,000	2,538,000
Purchases of premises, furniture, and equipment	(7,680,000)	(13,540,000)
Net cash received from (paid for) acquisition	142,282,000	(13,532,000)
Net cash used in investing activities	(1,189,082,000)	(1,000,192,000)
Financing Activities
Net increase in deposit accounts	1,570,219,000	370,061,000
Net increase in borrowed funds	286,890,000	745,665,000
Swap termination costs	(14,285,000)	0
Net proceeds from the issuance of preferred stock	221,047,000	0
Repurchases of common stock	(22,557,000)	(33,928,000)
Cash dividends paid	(52,522,000)	(41,138,000)
Restricted stock activity	(3,063,000)	(3,833,000)
Net cash provided by financing activities	1,985,729,000	1,036,827,000
Net increase in cash and cash equivalents	891,519,000	186,409,000
Cash and cash equivalents at beginning of period	299,221,000	289,258,000
Cash and cash equivalents at end of period	1,190,740,000	475,667,000
Supplemental Disclosures of Cash Flow Information:
Income taxes paid	40,012,000	29,331,000
Interest paid to depositors and creditors	65,198,000	80,017,000
Dividends declared, but unpaid	15,859,000	15,281,000
Stock issued for acquisitions, net of issuance costs	71,883,000	101,496,000
Non-cash transfers of loans to OREO	121,000	519,000
Non-cash transfers of loans to other assets	0	13,175,000
Non-cash transfer of loans held-for-sale to loans held-for-investment	(243,000)
Non-cash transfers of loans held-for-investment to loans held-for-sale		9,444,000
Non-cash recognition of right-of-use asset/liability	$ 0	$ 143,561,000