Consolidated Statements of Cash Flow (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 42,520	$ 22,608
Adjustments to reconcile to net cash provided by operating activities:
Provision for credit losses		19,583
Depreciation and amortization	4,670	4,455
Net amortization of securities premiums and discounts	369	(461)
Realized securities gains	(95)	(50)
Gain on sales of loans	(2,010)	(781)
Cash receipts from the sale of loans originated for sale	114,517	56,879
Cash disbursements for loans originated for sale	(98,043)	(61,258)
Deferred income tax benefit	(738)	(1,211)
Gain on sale of other assets	(2,584)	(2,183)
Decrease in interest receivable	235	196
Decrease in interest payable	(329)	(543)
Amortization of stock-based compensation arrangements	576	426
Excess tax benefit from stock-based compensation arrangements	(1,551)	(95)
Other, net	10,833	(2,302)
Net cash provided by operating activities	68,370	35,263
INVESTING ACTIVITIES
Net cash received from acquisitions, net of cash paid		18,397
Net cash paid from sale of assets and liabilities, net of cash received	(13,733)
Net increase in federal funds sold		1,000
Purchases of held for investment debt securities		(295)
Purchases of available for sale debt securities	(210,662)	(234,059)
Proceeds from maturities, calls and paydowns of held for investment debt securities	7	237
Proceeds from maturities, calls and paydowns of available for sale debt securities	243,597	142,818
Purchase of equity securities	(171)	(39)
Proceeds from paydowns and sales of equity securities	194	408
Net change in loans	32,053	(308,102)
Purchases of premises, equipment and computer software	(7,718)	(11,349)
Purchase of tax credits	(1,262)	(219)
Other, net	2,858	4,988
Net cash provided by (used in) investing activities	45,163	(386,215)
FINANCING ACTIVITIES
Net change in deposits	1,344,608	44,559
Net change in short-term borrowings	2,650	300
Issuance of common stock in connection with stock options, net	1,309	232
Common stock acquired		(3,098)
Net cash settlement of options	(5,479)
Cash dividends paid	(11,125)	(10,462)
Net cash provided by financing activities	1,331,963	31,531
Net increase/(decrease) in cash, due from banks and interest-bearing deposits	1,445,496	(319,421)
Cash, due from banks and interest-bearing deposits at the beginning of the period	1,616,912	1,868,281
Cash, due from banks and interest-bearing deposits at the end of the period	3,062,408	1,548,860
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Cash paid during the period for interest	3,155	10,410
Cash paid during the period for income taxes	1,300	1,175
Noncash investing and financing activities:
Fair value of assets acquired in acquisitions		47,838
Liabilities assumed in acquisitions		45,040
Unpaid common stock dividends declared	$ 11,134	$ 10,463