Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
OPERATING ACTIVITIES
Net income	$ 65,095	$ 67,420
Adjustments to reconcile net income to net cash (used in) provided by operating activities:
Depreciation and amortization	11,637	12,323
Provision for credit losses	(19,914)	1,445
(Gain) loss on sale of investments	54	(5,471)
Net accretion of investment securities and assets	(13,176)	(12,018)
Net amortization on borrowings	111	134
Stock-based compensation expense	3,941	3,852
Gain on sale of premises and equipment, net of impairment	0	(177)
Gain on sale of foreclosed assets and other real estate owned	(235)	(134)
Gain on sale of mortgage loans held for sale	(2,931)	(11,409)
Gain on sale of branches	0	(5,300)
Deferred income taxes	9,107	3,227
Income from bank owned life insurance	(2,706)	(1,534)
Originations of mortgage loans held for sale	(189,361)	(298,914)
Proceeds from sale of mortgage loans held for sale	210,442	384,046
Changes in assets and liabilities:
Interest receivable	3,633	1,237
Other assets	(19,178)	(30,187)
Accrued interest and other liabilities	(5,045)	(20,733)
Income taxes payable	9,051	(12,055)
Net cash provided by operating activities	60,525	75,752
INVESTING ACTIVITIES
Net change in loans	(22,060)	705,540
Proceeds from sale of loans	1,237	1,847
Net change in due from banks - time	25	245
Purchases of premises and equipment, net	(7,156)	(2,514)
Proceeds from sale of premises held for sale	0	1,572
Proceeds from sale of foreclosed assets held for sale	1,623	8,338
Proceeds from sale of available-for-sale securities	0	135,651
Proceeds from maturities of available-for-sale securities	194,961	185,636
Purchases of available-for-sale securities	(162,359)	(1,464,377)
Proceeds from maturities of held-to-maturity securities	17,491	4,426
Purchases of held-to-maturity securities	(44,638)	(280,043)
Proceeds from bank owned life insurance death benefits	0	573
Disposition of assets and liabilities held for sale	0	(134,166)
Net cash used in investing activities	(20,876)	(837,272)
FINANCING ACTIVITIES
Net change in deposits	25,874	1,192,740
Dividends paid on preferred stock	0	(13)
Dividends paid on common stock	(21,375)	(19,500)
Net change in other borrowed funds	(730)	(1,600)
Net change in federal funds purchased and securities sold under agreements to repurchase	11,425	23,942
Net shares (cancelled) issued under stock compensation plans	(3,575)	1,172
Shares issued under employee stock purchase plan	1,151	1,170
Repurchases of common stock	(16,055)	(3,080)
Net cash (used in) provided by financing activities	(3,285)	1,194,831
INCREASE IN CASH AND CASH EQUIVALENTS	36,364	433,311
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	1,650,653	3,472,152
CASH AND CASH EQUIVALENTS, END OF PERIOD	$ 1,687,017	$ 3,905,463