Parent Company Information - Schedule of Condensed Statements of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net Income	$ 473,840	$ 390,606	$ 309,793
Adjustments to reconcile net income to net cash provided by operating activities:
Stock-based compensation	20,887	16,154	14,726
Net amortization of premiums and accretion of discounts on borrowings	30,251	38,315	29,512
Net change in:
Other assets	122,241	(311,760)	(163,330)
Accrued expenses and other liabilities	(63,653)	58,234	57,882
Net cash provided by operating activities	837,142	163,561	261,923
Cash flows from investing activities:
Purchases of equity securities	(4,051)	(8,337)	(14,776)
Cash and cash equivalents acquired in acquisitions, net	321,618	0	22,239
Net cash used in investing activities	(1,080,781)	(2,037,662)	(897,319)
Cash flows from financing activities:
Proceeds from issuance of long-term borrowings, net	295,922	838,388	950,000
Repayment of long-term borrowings	(1,168,465)	(679,775)	(921,995)
Dividends paid to preferred shareholders	(12,688)	(12,688)	(12,688)
Dividends paid to common shareholders	(179,667)	(177,965)	(146,537)
Purchase of common shares to treasury	(23,907)	(5,374)	(1,805)
Common stock issued, net	11,245	2,202	2,957
Net cash provided by financing activities	964,354	2,768,619	641,454
Net change in cash and cash equivalents	720,715	894,518	6,058
Cash and cash equivalents at beginning of year	1,329,205	434,687	428,629
Cash and cash equivalents at end of year	2,049,920	1,329,205	434,687
Parent Company
Cash flows from operating activities:
Net Income	473,840	390,606	309,793
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in undistributed earnings of subsidiaries	(341,365)	(219,687)	(197,714)
Stock-based compensation	20,887	16,154	14,726
Net amortization of premiums and accretion of discounts on borrowings	1,152	230	124
Net change in:
Other assets	2,134	121	19,768
Accrued expenses and other liabilities	(7,079)	17,905	8,803
Net cash provided by operating activities	149,569	205,329	155,500
Cash flows from investing activities:
Purchases of equity securities	(1,644)	(2,500)	0
Cash and cash equivalents acquired in acquisitions, net	(3,983)	0	11,947
Repayment of subordinated debt by subsidiary	0	100,000	0
Capital contributions to subsidiary	(227,000)	(210,000)	0
Other, net	0	(1,200)	0
Net cash used in investing activities	(232,627)	(113,700)	11,947
Cash flows from financing activities:
Proceeds from issuance of long-term borrowings, net	295,922	113,146	0
Repayment of long-term borrowings	(60,000)	0	0
Dividends paid to preferred shareholders	(12,688)	(12,688)	(12,688)
Dividends paid to common shareholders	(179,667)	(177,965)	(146,537)
Purchase of common shares to treasury	(23,907)	(5,374)	(1,805)
Common stock issued, net	11,245	2,202	2,957
Net cash provided by financing activities	30,905	(80,679)	(158,073)
Net change in cash and cash equivalents	(52,153)	10,950	9,374
Cash and cash equivalents at beginning of year	130,163	119,213	109,839
Cash and cash equivalents at end of year	$ 78,010	$ 130,163	$ 119,213