Consolidated Statement of Changes in Shareholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Preferred Stock	Common Stock Issuable	Capital Surplus	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Beginning balance (in shares) at Dec. 31, 2022		106,222,758
Beginning balance at Dec. 31, 2022	$ 2,700,674	$ 106,223	$ 96,422	$ 12,307	$ 2,306,366	$ 508,844	$ (329,488)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	62,300					62,300
Other comprehensive income	35,051						35,051
Impact of acquisitions (in shares)		8,770,531
Impact of acquisitions	306,461	$ 8,771			297,690
Preferred stock dividends	(1,719)					(1,719)
Common stock dividends	(26,819)					(26,819)
Impact of equity-based compensation awards (in shares)		121,888
Impact of equity-based compensation awards	2,520	$ 122		498	1,900
Impact of other United sponsored equity plans (in shares)		36,389
Impact of other United sponsored equity plans	(345)	$ 36		(828)	447
Ending balance (in shares) at Mar. 31, 2023		115,151,566
Ending balance at Mar. 31, 2023	$ 3,078,123	$ 115,152	96,422	11,977	2,606,403	542,606	(294,437)
Beginning balance (in shares) at Dec. 31, 2023	119,010,319	119,010,319
Beginning balance at Dec. 31, 2023	$ 3,261,525	$ 119,010	88,266	13,110	2,699,112	581,219	(239,192)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	62,631					62,631
Other comprehensive income	2,557						2,557
Impact of acquisitions	0
Preferred stock dividends	(1,573)					(1,573)
Common stock dividends	(27,665)					(27,665)
Impact of equity-based compensation awards (in shares)		80,147
Impact of equity-based compensation awards	3,112	$ 80		76	2,956
Impact of other United sponsored equity plans (in shares)		46,052
Impact of other United sponsored equity plans	$ (477)	$ 47		(1,263)	739
Ending balance (in shares) at Mar. 31, 2024	119,136,518	119,136,518
Ending balance at Mar. 31, 2024	$ 3,300,110	$ 119,137	$ 88,266	$ 11,923	$ 2,702,807	$ 614,612	$ (236,635)