Parent Company Only Condensed Financial Statements - Consolidated Statements of Cash Flow (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash flows from operating activities:
Net income available to common shareholders		$ 190,309	$ 199,002	$ 133,055
Adjustments to reconcile net income to net cash provided by operating activities:
Share-based compensation		10,146	8,006	6,017
Net cash provided by operating activities		268,238	216,640	160,575
Cash flows from investing activities:
Net cash paid for acquisitions and dispositions		0	0	212,642
Net cash used in investing activities		(1,307,782)	(1,383,784)	(23,114)
Cash flows from financing activities:
Repayments of Subordinated Debt		0	0	50,000
Dividends paid on common stock		(37,368)	(33,602)	(26,153)
Payments for Repurchase of Common Stock		0	32,923	60,589
Proceeds from issuance of preferred stock, net	$ 72,000	0	0	71,988
Dividends paid on preferred stock		(3,750)	(4,041)	0
Net cash provided by financing activities		1,181,214	(563,186)	1,346,525
Net increase in cash and cash equivalents		$ 141,670	$ (1,730,330)	$ 1,483,986
Noncash investing and financing transactions:
Common shares issued in connection with acquisitions		0	0	343,650
Parent [Member]
Cash flows from operating activities:
Net income available to common shareholders		$ 194,059	$ 203,043	$ 133,055
Adjustments to reconcile net income to net cash provided by operating activities:
Share-based compensation		4,439	8,006	6,017
Net income of subsidiaries		(203,433)	(216,777)	(148,188)
Dividends from subsidiaries		49,875	76,700	97,000
Other, net		(421)	6,102	(16)
Net cash provided by operating activities		44,519	77,074	87,868
Cash flows from investing activities:
Net cash paid for acquisitions and dispositions		0	0	2,346
Purchases of other investments		(1,002)	(2,187)	(2,204)
Proceeds from distributions on other investments		3,314	3,878	2,656
Net cash used in investing activities		2,312	1,691	2,798
Cash flows from financing activities:
Repayments of Subordinated Debt		0	0	(50,000)
Payments for the redemption of subordinated notes		(5,714)	(5,714)	(7,143)
Dividends paid on common stock		(37,368)	(33,602)	(26,153)
Payments for Repurchase of Common Stock		0	32,923	60,589
Proceeds from issuance of preferred stock, net		0	0	71,988
Dividends paid on preferred stock		(3,750)	(4,041)	0
Payments for the repurchase of equity instruments, net		1,401	1,773	516
Net cash provided by financing activities		(45,431)	(74,507)	(71,381)
Net increase in cash and cash equivalents		1,400	4,258	19,285
Cash and cash equivalents, beginning of period		99,018	94,760	75,475
Cash and cash equivalents, end of period	$ 94,760	$ 100,418	$ 99,018	$ 94,760
Noncash investing and financing transactions:
Common shares issued in connection with acquisitions		0	0	343,650