Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Cash flows from operating activities
Net income	$ 103,360	$ 74,262
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses	17,971	(3,990)
Depreciation and amortization	11,425	11,680
Change in MSRs valuation	1,857	(9,451)
Amortization of other intangible assets	2,203	2,203
Amortization and accretion on earning assets, funding, and other, net	338	5,338
Net amortization of tax credit investments	8,574	8,535
(Gains) on sales of investment securities, net	0	(21)
Asset (gains), net	(263)	(188)
Loss on mortgage banking activities, net	251	4,183
Mortgage loans originated and acquired for sale	(69,254)	(252,113)
Proceeds from sales of mortgage loans held for sale	54,652	296,089
Changes in certain assets and liabilities:
(Increase) in interest receivable	(7,955)	(2,592)
(Decrease) increase in interest payable	14,775	(1,917)
(Decrease) in expense payable	(52,396)	(46,737)
(Decrease) increase in net derivative position	(42,403)	152,545
Net change in other assets and other liabilities	4,336	8,292
Net cash provided by operating activities	47,470	246,119
Cash flows from investing activities
Net (increase) in loans	(414,268)	(305,878)
Purchases of:
AFS securities	(681,386)	(409,076)
HTM securities	(41,524)	(135,301)
Federal Home Loan Bank and Federal Reserve Bank stocks and equity securities	(56,892)	(301)
Proceeds from:
Sales of AFS securities	0	734
Sale of Federal Home Loan Bank and Federal Reserve Bank stocks and equity securities	15,765	8
Prepayments, calls, and maturities of AFS securities	79,746	167,986
Prepayments, calls, and maturities of HTM securities	33,053	51,206
Sales, prepayments, calls, and maturities of other assets	10,115	18,012
Net change in tax credit and alternative investments	(7,033)	(10,293)
Premises, equipment, and software, net of disposals	(13,898)	(17,141)
Net cash (used in) investing activities	(1,076,322)	(640,045)
Cash flows from financing activities
Net increase (decrease) in deposits	695,723	(60,949)
Net increase (decrease) in short-term funding	(379,329)	45,098
Net increase in short-term FHLB advances	660,000	320,000
Repayment of long-term FHLB advances	(507)	(414,578)
Proceeds from long-term FHLB advances	115	11,506
Proceeds from issuance of long-term funding	292,740	0
(Repayment) proceeds of finance lease principal	(21)	399
Proceeds from issuance of common stock for stock-based compensation plans	1,766	6,654
Cash dividends on common stock	(32,013)	(30,583)
Cash dividends on preferred stock	(2,875)	(2,875)
Net cash provided by (used in) financing activities	1,230,238	(130,521)
Net increase (decrease) in cash and cash equivalents	201,385	(524,447)
Cash and cash equivalents at beginning of period	621,455	1,025,515	$ 1,025,515
Cash and cash equivalents at end of period(a)	822,840	501,068	621,455
Supplemental disclosures of cash flow information
Cash paid for interest	153,760	16,267
Cash paid for (received from) income and franchise taxes	1,086	(1,471)
Loans and bank premises transferred to OREO	3,599	426
Capitalized mortgage servicing rights	474	3,042	$ 7,279
Loans transferred into held for sale from portfolio, net	94	2,644
Transfer of AFS securities to HTM securities	0	1,621,990
Unsettled trades to purchase securities	0	4,246
Change in Unrealized Gain (Loss) on Hedged Item in Fair Value Hedge	(10,724)	0
Unrealized Gain (Loss) on Cash Flow Hedging Instruments	13,763	0
Fair Value, Measurements, Recurring
Supplemental disclosures of cash flow information
Unrealized Gain (Loss) on Cash Flow Hedging Instruments	10,331	0
Performance/Service Based RSAs, RSA,
Cash flows from financing activities
Purchase of treasury stock, open market purchases	(5,362)	(5,193)
Retained Earnings [Member]
Cash flows from operating activities
Net income	$ 103,360	$ 74,262