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, Preferred	Treasury Stock, Common
Increase (Decrease) in Stockholders' Equity [Roll Forward]
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				17,655,410
Beginning Balances at Dec. 31, 2021		$ 774,130		$ 8,593		$ 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
Stock Issued During The Period Value Retirement Savings Plan And Dividend Reinvestment Plan				$ 18		4,977
Share-based compensation (shares)				46,590
Share-based compensation and tax benefit		4,995		$ 23		2,122
Treasury stock activities		2,145					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
Stock Issued During The Period Value Retirement Savings Plan And 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)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares Held In Trust For Deferred Compensation Plan		107,659
Preferred Stock, Shares Authorized		2,000,000,000
Preferred Stock, Par or Stated Value Per Share		$ 10.00
Shares Held In Trust For Deferred Compensation Plan		108,143
Common Stock, Dividends, Per Share, Declared		$ 1.715
Beginning Balances (shares) at Dec. 31, 2022	[1],[2]			17,741,418
Beginning Balances at Dec. 31, 2022		$ 832,801		$ 8,635	[1],[2]	380,036	445,509	(1,379)	7,060		(7,060)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income		61,884					61,884
Other comprehensive income (loss)		242						242
Other Comprehensive Income (Loss), Net of Tax		242
Dividend declared		(30,792)					(30,792)
Retirement savings plan and dividend reinvestment plan (shares)				0
Stock Issued During The Period Value Retirement Savings Plan And Dividend Reinvestment Plan		(21)		$ 0		(21)
Share-based compensation (shares)	[3],[4]			55,323
Share-based compensation and tax benefit	[3],[4]	2,563		$ 27		2,536
Treasury stock activities							0		1,927		(1,927)
Ending Balances (shares) at Sep. 30, 2023	[1]			17,796,741
Ending Balances at Sep. 30, 2023		$ 866,677	[1]	$ 8,662	[1]	382,551	476,601	(1,137)	8,987		(8,987)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation		19,859
Common Stock, Dividends, Per Share, Declared		$ 0.5900
Beginning Balances (shares) at Jun. 30, 2023				17,796,741
Beginning Balances at Jun. 30, 2023		$ 864,228		$ 8,662		380,830	477,795	(3,059)	9,001		(9,001)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income		9,407					9,407
Other comprehensive income (loss)		1,922						1,922
Other Comprehensive Income (Loss), Net of Tax		1,922
Dividend declared		(10,601)					(10,601)
Retirement savings plan and dividend reinvestment plan (shares)				0
Stock Issued During The Period Value Retirement Savings Plan And Dividend Reinvestment Plan		(2)		$ 0		(2)
Share-based compensation (shares)				0
Share-based compensation and tax benefit		1,723		$ 0		1,723
Treasury stock activities							0		(14)		14
Ending Balances (shares) at Sep. 30, 2023	[1]			17,796,741
Ending Balances at Sep. 30, 2023		$ 866,677	[1]	$ 8,662	[1]	$ 382,551	$ 476,601	$ (1,137)	$ 8,987		$ (8,987)
Preferred Stock, Shares Authorized		2,000,000
Preferred Stock, Par or Stated Value Per Share		$ 10.00
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares Held In Trust For Deferred Compensation Plan		106,960

[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 106,960, 108,143, 107,659, and 116,238 shares at September 30, 2023, December 31, 2022, September 30, 2022 and December 31, 2021, respectively, held in a Rabbi Trust related to our Non-Qualified Deferred Compensation Plan.(3)Can include shares issued under the Retirement Savings Plan, DRIP and ATM equity issuances.

[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, 2023 and 2022, we withheld 19,859 and 21,832 shares, respectively, for employee taxes.