Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands		Total		Common Stock [Member]		Additional Paid-In Capital [Member]		Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Deferred Compensation [Member]	Treasury Stock [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares Held In Trust For Deferred Compensation Plan		105,087
Common Stock, Dividends, Per Share, Declared		$ 1.4
Beginning Balances (shares) at Dec. 31, 2020	[1],[2]			17,461,841
Beginning Balances at Dec. 31, 2020		$ 697,085	[1],[2]	$ 8,499	[1],[2]	$ 348,482		$ 342,969	$ (2,865)	$ 5,679	$ (5,679)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income		60,754						60,754
Other comprehensive income (loss)		5,304							5,304
Other Comprehensive Income (Loss), Net of Tax		5,304
Dividend declared		(24,826)						(24,826)
Retirement savings plan and dividend reinvestment plan (shares)				80,022
Dividend reinvestment plan		9,286		$ 39		9,247
Share-based compensation (shares)	[3],[4]			45,971
Share-based compensation and tax benefit		3,359		$ 22	[3],[4]	3,337	[3],[4]
Treasury stock activities		0								1,507	(1,507)
Ending Balances (shares) at Sep. 30, 2021	[1]			17,587,834
Ending Balances at Sep. 30, 2021		$ 750,962	[1]	$ 8,560	[1]	361,066		378,897	2,439	7,186	(7,186)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation		14,020
Common Stock, Dividends, Per Share, Declared		$ 0.4800
Beginning Balances (shares) at Jun. 30, 2021				17,567,928
Beginning Balances at Jun. 30, 2021		$ 741,564		$ 8,550		357,520		374,936	558	7,203	(7,203)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income		12,475						12,475
Other comprehensive income (loss)		1,881							1,881
Other Comprehensive Income (Loss), Net of Tax		1,881
Dividend declared		(8,514)						(8,514)
Retirement savings plan and dividend reinvestment plan (shares)				19,906
Dividend reinvestment plan		2,451		$ 10		2,441
Share-based compensation (shares)				0
Share-based compensation and tax benefit		1,105		$ 0		1,105
Treasury stock activities		0								(17)	17
Ending Balances (shares) at Sep. 30, 2021	[1]			17,587,834
Ending Balances at Sep. 30, 2021		$ 750,962	[1]	$ 8,560	[1]	361,066		378,897	2,439	7,186	(7,186)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares Held In Trust For Deferred Compensation Plan		114,016
Preferred Stock, Shares Authorized		2,000,000
Preferred Stock, Par or Stated Value Per Share		$ 0.01
Shares Held In Trust For Deferred Compensation Plan		116,238
Common Stock, Dividends, Per Share, Declared		$ 1.550
Beginning Balances (shares) at Dec. 31, 2021	[1],[2]			17,655,410
Beginning Balances at Dec. 31, 2021		$ 774,130		$ 8,593	[1],[2]	371,162		393,072	1,303	7,240	(7,240)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income		63,646						63,646
Other comprehensive income (loss)		(2,701)							(2,701)
Other Comprehensive Income (Loss), Net of Tax		(2,701)
Dividend declared		(27,777)						(27,777)
Retirement savings plan and dividend reinvestment plan (shares)				36,785
Dividend reinvestment plan		4,995		$ 18		4,977
Share-based compensation (shares)	[3],[4]			46,590
Share-based compensation and tax benefit	[3],[4]	2,145		$ 23		2,122
Treasury stock activities								0		(237)	237
Ending Balances (shares) at Sep. 30, 2022	[1]			17,738,785
Ending Balances at Sep. 30, 2022		$ 814,438	[1]	$ 8,634	[1]	378,261		428,941	(1,398)	7,003	(7,003)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation		21,832
Common Stock, Dividends, Per Share, Declared		$ 0.5350
Beginning Balances (shares) at Jun. 30, 2022				17,734,794
Beginning Balances at Jun. 30, 2022		$ 815,701		$ 8,632		376,866		428,833	1,370	7,018	(7,018)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income		9,662						9,662
Other comprehensive income (loss)		(2,768)							(2,768)
Other Comprehensive Income (Loss), Net of Tax		(2,768)
Dividend declared		(9,554)						(9,554)
Retirement savings plan and dividend reinvestment plan (shares)				2,939
Dividend reinvestment plan		365		$ 1		364
Share-based compensation (shares)				1,052
Share-based compensation and tax benefit		1,032		$ 1		1,031
Treasury stock activities								0		(15)	15
Ending Balances (shares) at Sep. 30, 2022	[1]			17,738,785
Ending Balances at Sep. 30, 2022		$ 814,438	[1]	$ 8,634	[1]	$ 378,261		$ 428,941	$ (1,398)	$ 7,003	$ (7,003)
Preferred Stock, Shares Authorized		2,000,000
Preferred Stock, Par or Stated Value Per Share		$ 0.01
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares Held In Trust For Deferred Compensation Plan		107,659

[1] 2,000,000 shares of preferred stock at $0.01 par value have been authorized. No shares have been issued or are outstanding; accordingly, no information has been included in the statements of stockholders’ equity.    

[2] Includes 107,659, 116,238, 114,016, and 105,087 shares at September 30, 2022, December 31, 2021, September 30, 2021 and December 31, 2020, respectively, held in a Rabbi Trust related to our Non-Qualified Deferred Compensation Plan.

[3] Includes amounts for shares issued for directors’ compensation.

[4] The shares issued under the SICP are net of shares withheld for employee taxes. For the nine months ended September 30, 2022 and 2021, we withheld 21,832 and 14,020 shares, respectively, for employee taxes.(5)Can include shares issued under the Retirement Savings Plan, DRIP and ATM equity issuances.