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		$ 0.92
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		48,279						48,279
Other comprehensive income (loss)		3,423							3,423
Other Comprehensive Income (Loss), Net of Tax		3,423
Dividend declared		(16,312)						(16,312)
Retirement savings plan and dividend reinvestment plan (shares)				60,116
Dividend reinvestment plan		6,835		$ 29		6,806
Share-based compensation (shares)	[3],[4]			45,971
Share-based compensation and tax benefit		2,254		$ 22	[3],[4]	2,232	[3],[4]
Treasury stock activities		0								1,524	(1,524)
Ending Balances (shares) at Jun. 30, 2021	[1]			17,567,928
Ending Balances at Jun. 30, 2021		$ 741,564	[1]	$ 8,550	[1]	357,520		374,936	558	7,203	(7,203)
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 Mar. 31, 2021				17,521,493
Beginning Balances at Mar. 31, 2021		$ 726,388		$ 8,528		350,875		369,623	(2,638)	6,992	(6,992)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income		13,813						13,813
Other comprehensive income (loss)		3,196							3,196
Other Comprehensive Income (Loss), Net of Tax		3,196
Dividend declared		(8,500)						(8,500)
Retirement savings plan and dividend reinvestment plan (shares)				39,605
Dividend reinvestment plan		4,621		$ 19		4,602
Share-based compensation (shares)				6,830
Share-based compensation and tax benefit		2,046		$ 3		2,043
Treasury stock activities		0								211	(211)
Ending Balances (shares) at Jun. 30, 2021	[1]			17,567,928
Ending Balances at Jun. 30, 2021		$ 741,564	[1]	$ 8,550	[1]	357,520		374,936	558	7,203	(7,203)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares Held In Trust For Deferred Compensation Plan		117,193
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		$ 1.015
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		53,985						53,985
Other comprehensive income (loss)		67							67
Other Comprehensive Income (Loss), Net of Tax		67
Dividend declared		(18,224)						(18,224)
Retirement savings plan and dividend reinvestment plan (shares)				33,846
Dividend reinvestment plan		4,630		$ 17		4,613
Share-based compensation (shares)	[3],[4]			45,538
Share-based compensation and tax benefit	[3],[4]	1,113		$ 22		1,091
Treasury stock activities								0		(222)	222
Ending Balances (shares) at Jun. 30, 2022	[1]			17,734,794
Ending Balances at Jun. 30, 2022		$ 815,701	[1]	$ 8,632	[1]	376,866		428,833	1,370	7,018	(7,018)
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 Mar. 31, 2022				17,719,388
Beginning Balances at Mar. 31, 2022		$ 805,512		$ 8,624		373,694		421,344	1,850	6,477	(6,477)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income		17,051						17,051
Other comprehensive income (loss)		(480)							(480)
Other Comprehensive Income (Loss), Net of Tax		(480)
Dividend declared		(9,562)						(9,562)
Retirement savings plan and dividend reinvestment plan (shares)				8,886
Dividend reinvestment plan		1,208		$ 5		1,203
Share-based compensation (shares)				6,520
Share-based compensation and tax benefit		1,972		$ 3		1,969
Treasury stock activities								0		541	(541)
Ending Balances (shares) at Jun. 30, 2022	[1]			17,734,794
Ending Balances at Jun. 30, 2022		$ 815,701	[1]	$ 8,632	[1]	$ 376,866		$ 428,833	$ 1,370	$ 7,018	$ (7,018)
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		110,835

[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 110,835, 116,238, 117,193, and 105,087 shares at June 30, 2022, December 31, 2021, June 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 six months ended June 30, 2022 and 2021, we withheld 21,832 and 14,020 shares, respectively, for employee taxes.(5)Includes the Retirement Savings Plan, DRIP and ATM equity issuances.