Condensed Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	ASR Plan [Member]	Common Stock [Member]	Common Stock [Member] ASR Plan [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Beginning balance at Dec. 31, 2020	$ 2,007,990		$ 1,211,780		$ 760,861	$ 35,349
Beginning balance, shares at Dec. 31, 2020			135,601
Repurchase of common stock	(534)		$ (534)
Repurchase of common stock, shares			(24)
Exercise of stock options	964		$ 964
Exercise of stock options, shares			45
Shares issued pursuant to stock-based compensation plan	2,672		$ 2,672
Shares issued pursuant to stock-based compensation plan, shares			305
Cash dividends declared on common stock	(48,992)				(48,992)
Net earnings	115,072				115,072
Other comprehensive income (loss)	(22,098)					(22,098)
Ending balance at Jun. 30, 2021	2,055,074		$ 1,214,882		826,941	13,251
Ending balance, shares at Jun. 30, 2021			135,927
Beginning balance at Mar. 31, 2021	2,020,666		$ 1,213,451		800,259	6,956
Beginning balance, shares at Mar. 31, 2021			135,920
Repurchase of common stock	(32)		$ (32)
Repurchase of common stock, shares			(2)
Exercise of stock options	73		$ 73
Exercise of stock options, shares			5
Shares issued pursuant to stock-based compensation plan	1,390		$ 1,390
Shares issued pursuant to stock-based compensation plan, shares			4
Cash dividends declared on common stock	(24,497)				(24,497)
Net earnings	51,179				51,179
Other comprehensive income (loss)	6,295					6,295
Ending balance at Jun. 30, 2021	2,055,074		$ 1,214,882		826,941	13,251
Ending balance, shares at Jun. 30, 2021			135,927
Beginning balance at Dec. 31, 2021	2,081,503		$ 1,209,903		875,568	(3,968)
Beginning balance, shares at Dec. 31, 2021			135,526
Repurchase of common stock	$ (40,464)	$ (70,000)	$ (40,464)	$ (70,000)
Repurchase of common stock, shares			(1,732)	(2,994)
Issuance of common stock for acquisition of Suncrest Bank			$ 8,617
Issuance of common stock for acquisition of Suncrest Bank, shares	197,069		197,069
Exercise of stock options	$ 965		$ 965
Exercise of stock options, shares			64
Shares issued pursuant to stock-based compensation plan	3,577		$ 3,577
Shares issued pursuant to stock-based compensation plan, shares			545
Cash dividends declared on common stock	(52,186)				(52,186)
Net earnings	104,618				104,618
Other comprehensive income (loss)	(242,871)					(242,871)
Ending balance at Jun. 30, 2022	1,982,211		$ 1,301,050		928,000	(246,839)
Ending balance, shares at Jun. 30, 2022			140,026
Beginning balance at Mar. 31, 2022	2,075,043		$ 1,325,644		895,661	(146,262)
Beginning balance, shares at Mar. 31, 2022			141,626
Repurchase of common stock	(26,821)		$ 26,821
Repurchase of common stock, shares			1,148	450
Exercise of stock options	245		$ 245
Exercise of stock options, shares			14
Shares issued pursuant to stock-based compensation plan	1,982		$ 1,982
Shares issued pursuant to stock-based compensation plan, shares			(16)
Cash dividends declared on common stock	(26,719)				26,719
Net earnings	59,058				59,058
Other comprehensive income (loss)	(100,577)					(100,577)
Ending balance at Jun. 30, 2022	$ 1,982,211		$ 1,301,050		$ 928,000	$ (246,839)
Ending balance, shares at Jun. 30, 2022			140,026