Consolidated Statements of Cash Flows (Unaudited) - USD ($)	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Operating activities
Net income	$ 73,225,000	$ 98,775,000
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses on loans	3,500,000	0
Depreciation, amortization and accretion	23,947,000	22,459,000
Deferred income tax expense	5,150,000	4,975,000
Funding of mortgage loans held for sale	(1,076,613,000)	(2,222,822,000)
Proceeds from sales of mortgage loans held for sale	1,345,924,000	2,249,240,000
Gains on sales of mortgage loans held for sale	(9,537,000)	(51,482,000)
Valuation adjustment to mortgage servicing rights	0	(13,561,000)
Gains on sales of securities	0	(1,357,000)
Gains on sales of premises and equipment	(236,000)	(687,000)
Stock-based compensation expense	6,290,000	5,142,000
Decrease in other assets	(2,867,000)	(15,117,000)
Decrease in other liabilities	(19,077,000)	(25,985,000)
Net cash provided by operating activities	349,706,000	49,580,000
Investing activities
Purchases of securities available for sale	(609,752,000)	(1,190,400,000)
Proceeds from sales of securities available for sale	0	155,391,000
Proceeds from call/maturities of securities available for sale	249,394,000	195,114,000
Purchases of securities held to maturity	(91,803,000)	0
Proceeds from call/maturities of securities held to maturity	17,262,000	0
Net (increase) decrease in loans	(555,936,000)	783,838,000
Purchases of premises and equipment	(5,865,000)	(12,953,000)
Proceeds from sales of premises and equipment	933,000	8,715,000
Purchase of bank-owned life insurance	(80,000,000)	(45,000,000)
Net change in FHLB stock	(3,526,000)	(1,207,000)
Proceeds from sales of other assets	1,524,000	3,378,000
Net cash paid in acquisition of businesses	(10,066,000)	0
Other, net	622,000	2,803,000
Net cash used in investing activities	(1,087,213,000)	(100,321,000)
Financing activities
Net increase in noninterest-bearing deposits	23,273,000	664,087,000
Net (decrease) increase in interest-bearing deposits	(165,068,000)	392,183,000
Net increase (decrease) in short-term borrowings	69,215,000	(6,407,000)
Repayment of long-term debt	(32,417,000)	(1,733,000)
Cash paid for dividends	(24,993,000)	(25,104,000)
Net cash (used in) provided by financing activities	(129,990,000)	1,023,026,000
Net (decrease) increase in cash and cash equivalents	(867,497,000)	972,285,000
Cash and cash equivalents at beginning of period	1,877,965,000	633,203,000
Cash and cash equivalents at end of period	1,010,468,000	1,605,488,000
Supplemental disclosures
Cash paid for interest	19,959,000	24,146,000
Cash paid for income taxes	6,367,000	31,443,000
Noncash transactions:
Transfers of loans to other real estate owned	1,284,000	2,503,000
Recognition of operating right-of-use assets	1,595,000	3,624,000
Recognition of operating lease liabilities	$ 1,595,000	$ 3,624,000