Consolidated Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Operating activities
Net income	$ 117,575	$ 70,194
Adjustments to reconcile net income to net cash provided by operating activities
Provision for loan losses	(11,354)	51,741
Depreciation and amortization of premises and equipment	7,339	7,378
Net amortization on securities	4,460	2,812
Amortization of intangible assets	2,157	2,573
Amortization of operating lease right-of-use assets	5,401	5,549
Excess tax benefit on stock-based compensation	(321)	(188)
Stock-based compensation expense	3,819	3,957
Bank owned life insurance income	(4,588)	(4,010)
Amortization of subordinated debt issuance costs	328	121
Proceeds from sale of loans held for sale	48,371	153,732
Originations of loans held for sale	(47,996)	(144,105)
Net gains on sale of loans held for sale	(280)	(1,892)
Net security (gains) losses	(568)	548
Net gains on sale of other real estate owned	(44)	(243)
Net change in other assets and other liabilities	10,951	(40,760)
Net cash provided by operating activities	135,250	107,407
Investing activities
Net cash used in acquisitions	0	(3,899)
Securities available for sale:
Proceeds from maturities, calls and principal paydowns	308,688	239,622
Purchases	(560,884)	(437,827)
Securities held to maturity:
Proceeds from maturities, calls and principal paydowns	149,200	181,143
Proceeds from sales	0	996
Purchases	(216,205)	(215,327)
Equity securities:
Proceeds from calls	1,000	0
Other:
Net increase in loans	(73,344)	(436,630)
Proceeds from Federal Home Loan Bank stock redemption	2,355	58,799
Purchases of Federal Reserve Bank and Federal Home Loan Bank stock	(163)	(42,663)
Proceeds from settlement of bank owned life insurance	3,571	531
Purchases of bank owned life insurance	(40,000)	0
Purchases of premises and equipment, net	(5,007)	(4,512)
Proceeds from sales of other real estate owned	784	1,113
Net cash used in investing activities	(430,005)	(658,654)
Financing activities
Net increase in deposits	1,113,486	1,370,363
Net decrease in short-term borrowings	(68,671)	(471,803)
Proceeds from issuance of subordinated debt	0	100,000
Payment of subordinated debt issuance costs	0	(2,178)
Repayments of long-term debt	(25,077)	(85)
Proceeds from the issuance of shares to employee and other stock plans	112	184
Cash paid by employer for tax-withholdings on stock issuance	(1,973)	(1,218)
Purchase of treasury stock	(14,083)	(7,980)
Cash dividends	(35,614)	(35,419)
Net cash provided by financing activities	968,180	951,864
Net increase in cash and cash equivalents	673,425	400,617
Cash and cash equivalents at beginning of period	672,681	216,843
Cash and cash equivalents at end of period	1,346,106	617,460
Cash paid during the period for:
Interest expense	17,161	26,373
Income taxes paid, net of refund	39,025	38,137
Noncash investing activities:
Loans transferred to other real estate owned	141	1,017
Acquisitions:
Fair value of assets acquired	$ 0	$ 3,328