Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands		Total	Common Stock Outstanding	Common Stock	Value of Shares Held in Rabbi Trust at Cost	Deferred Compensation Obligation	Additional Paid in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Beginning balance at Dec. 31, 2018		$ 1,073,490		$ 279	$ (4,718)	$ 4,718	$ 527,648	$ 546,736	$ (1,173)
Beginning balance (in shares) at Dec. 31, 2018			28,080,408
Net income		165,175						$ 165,175
Other comprehensive income		19,342							19,342
Common Stock, Dividends, Per Share, Declared								$ 1.76
Common dividend declared		(57,729)						$ (57,729)
Common stock issued for acquisition		499,693		61			499,632
Common stock issued for acquisition (in shares)			6,166,010
Proceeds from exercise of stock options, net of cash paid		281					281
Proceeds from exercise of stock options (in shares)			14,646
Stock based compensation		4,403					4,403
Restricted stock awards issued, net of awards surrendered (in shares)			50,080
Restricted stock awards issued, net of awards surrendered		(1,463)		1			(1,464)
Stock Issued During Period, Shares, Other			66,244
Stock Issued During Period, Value, Other		4,951		1			4,950
Increase (Decrease) in Deferred Compensation					(17)	17
Ending balance (in shares) at Dec. 31, 2019			34,377,388
Ending balance at Dec. 31, 2019		1,708,143		342	(4,735)	4,735	1,035,450	654,182	18,169
Prior Period Reclassification Adjustment	[1]	1,553						1,553
Net income		121,167						$ 121,167
Other comprehensive income		22,526							22,526
Common Stock, Dividends, Per Share, Declared								$ 1.84
Common dividend declared		(60,878)						$ (60,878)
Common stock issued for acquisition		0
Proceeds from exercise of stock options, net of cash paid		197		0			197
Proceeds from exercise of stock options (in shares)			8,873
Stock based compensation		4,123					4,123
Restricted stock awards issued, net of awards surrendered (in shares)			47,182
Restricted stock awards issued, net of awards surrendered		(1,187)		1			(1,188)
Stock Issued During Period, Shares, Other			32,249
Stock Issued During Period, Value, Other		2,132		0			2,132
Stock Repurchased During Period, Shares			(1,500,000)
Stock Repurchased During Period, Value		(95,091)		(15)			(95,076)
Increase (Decrease) in Deferred Compensation		$ 0
Increase (Decrease) in Deferred Compensation and Other Retirement Benefits					1,669	(1,669)
Ending balance (in shares) at Dec. 31, 2020		32,965,692	32,965,692
Ending balance at Dec. 31, 2020		$ 1,702,685		328	(3,066)	3,066	945,638	716,024	40,695
Off-Balance Sheet, Credit Loss, Liability, Change in Method, Credit Loss Expense (Reversal)		(1,000)
Off-Balance Sheet, Credit Loss, Liability, Change in Method, Credit Loss Expense (Reversal), net of tax.		736
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method		(1,137)
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method, net of tax.		817
Net income		120,992						$ 120,992
Other comprehensive income		(38,512)							(38,512)
Common Stock, Dividends, Per Share, Declared								$ 1.92
Common dividend declared		(70,300)						$ (70,300)
Common stock issued for acquisition		1,298,558		143			1,298,415
Common stock issued for acquisition (in shares)			14,299,720
Proceeds from exercise of stock options (in shares)			4,744
Stock Repurchased During Period, Value, as a result of Stock Options Exercised		(57)					(57)
Stock based compensation		4,309					4,309
Restricted stock awards issued, net of awards surrendered (in shares)			53,768
Restricted stock awards issued, net of awards surrendered		(1,249)		1			(1,250)
Stock Issued During Period, Shares, Other			25,854
Stock Issued During Period, Value, Other		2,023					2,023
Increase (Decrease) in Deferred Compensation		$ 0
Increase (Decrease) in Deferred Compensation and Other Retirement Benefits					(80)	80
Ending balance (in shares) at Dec. 31, 2021		47,349,778	47,349,778
Ending balance at Dec. 31, 2021		$ 3,018,449		$ 472	$ (3,146)	$ 3,146	$ 2,249,078	$ 766,716	$ 2,183

[1] Represents adjustment needed to reflect the cumulative impact on retained earnings pursuant to the Company's adoption of Accounting Standards Update 2016-13. The adjustment presented includes $1.1 million ($817,000, net of tax) attributable to the change in accounting methodology for estimating the allowance for credit losses and $1.0 million ($736,000, net of tax) related to the reserve for unfunded commitments resulting from the Company's adoption of the standard. Amount shown in the table above is presented net of tax.