CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating Activities
Net income	$ 222,927	$ 303,202	$ 284,757
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses	14,795	19,963	23,076
Net amortization of debt securities	15,506	29,587	47,299
Net amortization of purchase accounting adjustments and deferred loan fees and costs	(5,347)	2,789	(17,881)
Origination of loans held for sale	(435,649)	(743,212)	(1,550,787)
Proceeds from loans held for sale	549,778	844,940	1,797,566
Gain on sale of loans	(12,202)	(20,032)	(63,063)
(Gain) loss on sale of securities	(1,510)	(620)	638
Bank-owned life insurance income, net	(3,849)	(3,579)	(2,873)
Stock-based compensation, net of tax benefits	5,929	5,366	4,349
Depreciation and amortization of premises and equipment	27,412	25,830	21,768
Gain on sale and write-downs of other real estate owned, net	(321)	(121)	(105)
Deferred tax expense (benefit)	507	2,177	(9,095)
Amortization of core deposit intangibles	9,731	10,658	10,271
Amortization of investments in variable interest entities	20,515	16,640	13,457
Net (increase) decrease in accrued interest receivable	(10,989)	(6,865)	5,118
Net (increase) decrease in other assets	(9,801)	(25,807)	8,188
Net increase (decrease) in accrued interest payable	121,576	1,922	(1,222)
Net (decrease) increase in other liabilities	(8,293)	7,822	588
Net cash provided by operating activities	500,715	470,660	572,049
Investing Activities
Sales of available-for-sale debt securities	29,972	326,302	0
Maturities, prepayments and calls of available-for-sale debt securities	621,878	1,101,420	1,453,049
Purchases of available-for-sale debt securities	0	(471,581)	(6,315,164)
Maturities, prepayments and calls of held-to-maturity debt securities	209,909	211,700	48,955
Purchases of held-to-maturity debt securities	0	(523,060)	(222,695)
Principal collected on loans	2,946,294	5,432,753	6,529,504
Loan originations	(4,013,701)	(7,296,411)	(7,000,632)
Net additions to premises and equipment	(49,283)	(23,238)	(9,436)
Proceeds from sale of other real estate owned	391	1,014	3,313
Proceeds from redemption of non-marketable equity securities	630,584	366,467	4,218
Purchases of non-marketable equity securities	(559,601)	(438,398)	(2)
Proceeds from bank-owned life insurance	1,787	2,217	2,112
Investments in variable interest entities	(25,722)	(40,967)	(22,640)
Net cash received from acquisitions	0	0	1,622,717
Net cash used in investing activities	(207,492)	(1,351,782)	(3,906,701)
Financing Activities
Net (decrease) increase in deposits	(676,652)	(729,707)	3,266,304
Net increase (decrease) in securities sold under agreements to repurchase	540,934	(74,878)	16,211
Net (decrease) increase in short-term Federal Home Loan Bank advances	(1,800,000)	1,800,000	0
Proceeds from short-term FRB Bank Term Funding advances	2,740,000	0	0
Net increase in other borrowed funds	3,327	9,120	3,526
Cash dividends paid	(146,690)	(157,540)	(145,557)
Tax withholding payments for stock-based compensation	(1,795)	(1,704)	(1,553)
Proceeds from stock option exercises	0	140	265
Net cash provided by financing activities	659,124	845,431	3,139,196
Net increase (decrease) in cash, cash equivalents and restricted cash	952,347	(35,691)	(195,456)
Cash, cash equivalents and restricted cash at beginning of period	401,995	437,686	633,142
Cash, cash equivalents and restricted cash at end of period	1,354,342	401,995	437,686
Supplemental Disclosure of Cash Flow Information
Cash paid during the period for interest	204,397	39,339	19,779
Cash paid during the period for income taxes	27,932	55,197	67,306
Supplemental Disclosure of Non-Cash Investing Activities
Transfer of debt securities from held-to-maturity to available-for-sale	0	2,154,475	844,020
Sale and refinancing of other real estate owned	22	0	0
Transfer of loans to other real estate owned	1,563	907	1,482
Right-of-use assets obtained in exchange for new lease liabilities	1,979	25,048	801
Dividends declared during the period but not paid	370	346	11,352
Acquisitions
Fair value of common stock shares issued	0	0	839,853
Cash consideration	0	0	9
Fair value of assets acquired	0	0	4,131,662
Liabilities assumed	$ 0	$ 0	$ 3,291,800