Condensed Financial Information (Parent Company Only) - Condensed Statements of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
OPERATING ACTIVITIES
Net income	$ 256,412	$ 271,156	$ 254,904
Items not requiring (providing) cash
Stock-based compensation expense	15,317	15,868	13,197
Deferred income taxes	14,933	10,937	(122)
Changes in:
Other assets	(7,214)	(33,495)	(7,480)
Net cash provided by operating activities	322,198	277,780	202,543
INVESTING ACTIVITIES
Net collections (originations) of loans	(1,900,325)	2,333,893	1,327,248
Net cash (used in) provided by investing activities	(946,233)	(2,537,736)	1,189,869
FINANCING ACTIVITIES
Stock repurchases	111,133	132,459	113,327
Dividends paid on preferred stock	0	(47)	(52)
Dividends paid on common stock	(94,096)	(78,845)	(74,593)
Retirement of preferred stock	0	(767)	0
Net cash (used in) provided by financing activities	(344,496)	438,457	1,083,117
INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(968,531)	(1,821,499)	2,475,529
CASH AND CASH EQUIVALENTS, BEGINNING OF YEAR	1,650,653	3,472,152	996,623
CASH AND CASH EQUIVALENTS, END OF YEAR	682,122	1,650,653	3,472,152
Parent Company
OPERATING ACTIVITIES
Net income	256,412	271,156	254,904
Items not requiring (providing) cash
Stock-based compensation expense	15,317	15,868	13,197
Depreciation and amortization	1,981	1,805	1,796
Deferred income taxes	(652)	3,347	1,583
Equity in undistributed net income (loss) of bank subsidiaries	(72,778)	(76,299)	29,345
Changes in:
Other assets	(26,775)	(2,099)	(27,056)
Other liabilities	(28,745)	11,109	7,790
Net cash provided by operating activities	144,760	224,887	281,559
INVESTING ACTIVITIES
Net collections (originations) of loans	1,198	(2,139)	186
Net (purchases of) proceeds from premises and equipment	(21)	(83)	(7)
(Advances to) repayment for subsidiaries	0	0	(15,363)
Cash acquired (paid) in business combinations	60,126	(6,818)	0
Other, net	1,688	2	185
Net cash (used in) provided by investing activities	62,991	(9,038)	(14,999)
FINANCING ACTIVITIES
(Repayment) issuance of long-term debt, net	(57,436)	(1,563)	(7,442)
Cancellation of common stock, net	(3,882)		(3,131)
Issuance of common stock, net		1,460
Stock repurchases	111,133	132,459	113,327
Dividends paid on preferred stock	0	(47)	(52)
Dividends paid on common stock	(94,096)	(78,845)	(74,593)
Retirement of preferred stock	0	(767)	0
Net cash (used in) provided by financing activities	(266,547)	(212,221)	(198,545)
INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(58,796)	3,628	68,015
CASH AND CASH EQUIVALENTS, BEGINNING OF YEAR	175,711	172,083	104,068
CASH AND CASH EQUIVALENTS, END OF YEAR	$ 116,915	$ 175,711	$ 172,083