Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating Activities
Net income	$ 303,202	$ 284,757	$ 266,400
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses	19,963	23,076	39,765
Net amortization of debt securities	29,587	47,299	16,893
Net amortization of purchase accounting adjustments and deferred loan fees and costs	2,789	(17,881)	(57,627)
Origination of loans held for sale	(743,212)	(1,550,787)	(2,070,843)
Proceeds from loans held for sale	844,940	1,797,566	2,093,549
Gain on sale of loans	(20,032)	(63,063)	(99,450)
(Gain) loss on sale of debt securities	(620)	638	(1,139)
Bank-owned life insurance income, net	(3,579)	(2,873)	(2,724)
Stock-based compensation, net of tax benefits	5,366	4,349	3,629
Depreciation and amortization of premises and equipment	25,830	21,768	20,420
(Gain) loss on sale and write-downs of other real estate owned, net	(121)	(105)	139
Deferred tax expense (benefit)	2,177	(9,095)	(6,863)
Amortization of core deposit intangibles	10,658	10,271	10,370
Amortization of investments in variable interest entities	16,640	13,457	11,282
Net (increase) decrease in accrued interest receivable	(6,865)	5,118	(17,663)
Net (increase) decrease in other assets	(25,807)	8,188	(20,926)
Net increase (decrease) in accrued interest payable	1,922	(1,222)	(1,507)
Net increase in other liabilities	7,822	588	5,840
Net cash provided by operating activities	470,660	572,049	189,545
Investing Activities
Sales of available-for-sale debt securities	326,302	0	0
Maturities, prepayments and calls of available-for-sale debt securities	1,101,420	1,453,049	758,879
Purchases of available-for-sale debt securities	(471,581)	(6,315,164)	(3,254,912)
Maturities, prepayments and calls of held-to-maturity debt securities	211,700	48,955	32,735
Purchases of held-to-maturity debt securities	(523,060)	(222,695)	0
Principal collected on loans	5,432,753	6,529,504	4,732,941
Loan originations	(7,296,411)	(7,000,632)	(5,864,038)
Net additions to premises and equipment	(23,238)	(9,436)	(11,717)
Proceeds from sale of other real estate owned	1,014	3,313	5,572
Proceeds from redemption of non-marketable equity securities	366,467	4,218	76,618
Purchases of non-marketable equity securities	(438,398)	(2)	(71,399)
Proceeds from bank-owned life insurance	2,217	2,112	0
Investments in variable interest entities	(40,967)	(22,640)	(12,088)
Net cash received from acquisitions	0	1,622,717	43,713
Net cash used in investing activities	(1,351,782)	(3,906,701)	(3,563,696)
Financing Activities
Net (decrease) increase in deposits	(729,707)	3,266,304	3,418,199
Net (decrease) increase in securities sold under agreements to repurchase	(74,878)	16,211	427,510
Net increase (decrease) in short-term Federal Home Loan Bank advances	1,800,000	0	(30,000)
Proceeds from long-term Federal Home Loan Bank advances	0	0	30,000
Repayments of long-term Federal Home Loan Bank advances	0	0	(38,589)
Net decrease in other borrowed funds	9,120	3,526	564
Cash dividends paid	(157,540)	(145,557)	(131,263)
Tax withholding payments for stock-based compensation	(1,704)	(1,553)	(1,082)
Proceeds from stock option exercises	140	265	993
Net cash provided by financing activities	845,431	3,139,196	3,676,332
Net (decrease) increase in cash, cash equivalents and restricted cash	(35,691)	(195,456)	302,181
Cash, cash equivalents and restricted cash at beginning of period	437,686	633,142	330,961
Cash, cash equivalents and restricted cash at end of period	401,995	437,686	633,142
Supplemental Disclosure of Cash Flow Information
Cash paid during the period for interest	39,339	19,779	28,822
Cash paid during the period for income taxes	55,197	67,306	63,021
Supplemental Disclosure of Non-Cash Investing Activities
Transfer of debt securities from held-to-maturity to available-for-sale	2,154,475	844,020	0
Sale and refinancing of other real estate owned	0	0	215
Transfer of loans to other real estate owned	907	1,482	2,076
Right-of-use assets obtained in exchange for new lease liabilities	25,048	801	7,406
Dividends declared during the period but not paid	346	11,352	14,572
Acquisitions
Fair value of common stock shares issued	0	839,853	112,133
Cash consideration	0	9	13,721
Fair value of assets acquired	0	4,131,662	745,420
Liabilities assumed	$ 0	$ 3,291,800	$ 619,566