Consolidated Statements of Stockholders' Equity - USD ($)		Total		Common Stock [Member]	Additional Paid-In Capital [Member]		Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Deferred Compensation [Member]	Treasury Stock [Member]
Shares, Issued	[1],[2]			16,378,545
Stockholders' Equity Attributable to Parent		$ 518,439,000	[2]	$ 7,971,000	$ 255,651,000		$ 261,530,000	$ (6,713,000)	$ 3,854,000	$ (3,854,000)
Net Income		65,153,000					65,153,000
Other comprehensive loss		561,000						561,000
Dividends		(26,191,000)					(26,191,000)
Stock Issued During The Period Shares Retirement Savings Plan And Dividend Reinvestment Plan				0
Stock Issued During The Period Value Retirement Savings Plan And Dividend Reinvestment Plan		(3,000)		$ 0	(3,000)
Share-based compensation, shares				25,231
Share-based compensation		3,618,000	[3],[4]	$ 13,000	3,605,000
Treasury stock activities		0							689,000	(689,000)
Tax Cuts and Jobs Act, Reclassification from AOCI to Retained Earnings, Tax Effect							115,000	(115,000)
Shares, Issued	[1],[2]			16,403,776
Stockholders' Equity Attributable to Parent		561,577,000	[2]	$ 7,984,000	259,253,000		300,607,000	(6,267,000)	4,543,000	(4,543,000)
Net Income		71,498,000					71,498,000
Other comprehensive loss		3,402,000						3,402,000
Dividends		(29,106,000)					(29,106,000)
Stock Issued, Value, During The Period Shares Retirement Savings Plan And Dividend Reinvestment Plan				$ 498,000	85,353,000
Stock Issued During The Period Value Retirement Savings Plan And Dividend Reinvestment Plan		85,851,000
Share-based compensation, shares	[3],[4]			34,456
Share-based compensation		3,893,000	[3],[4]	$ 17,000	3,876,000	[3],[4]
Treasury stock activities									1,136,000	(1,136,000)
New Accounting Pronouncement of Change in Accounting Principle, Effect of Adoption		$ (30,000)					(30,000)
Stock Issued During Period, Shares, Dividend Reinvestment Plan		300,000		1,023,609
Stock Issued During Period, Value, Dividend Reinvestment Plan		$ 86.12
Shares, Issued	[1],[2]			17,461,841
Stockholders' Equity Attributable to Parent		697,085,000		$ 8,499,000	348,482,000		342,969,000	(2,865,000)	5,679,000	(5,679,000)
Net Income		83,466,000
Other comprehensive loss		4,168,000						4,168,000
Dividends		(33,363,000)					(33,363,000)
Stock Issued, Value, During The Period Shares Retirement Savings Plan And Dividend Reinvestment Plan		18,248,000		$ 72,000	18,176,000
Stock Issued During The Period Shares Retirement Savings Plan And Dividend Reinvestment Plan				147,256
Share-based compensation, shares	[3],[4]			46,313
Share-based compensation		$ 4,526,000	[3],[4]	$ 22,000	4,504,000
Treasury stock activities									1,561,000	(1,561,000)
Stock Issued During Period, Shares, Dividend Reinvestment Plan		100,000
Stock Issued During Period, Value, Dividend Reinvestment Plan		$ 125.71
Shares, Issued	[1],[2]			17,655,410
Stockholders' Equity Attributable to Parent		$ 774,130,000		$ 8,593,000	$ 371,162,000		$ 393,072,000	$ 1,303,000	$ 7,240,000	$ (7,240,000)

[1] 2,000,000 shares of preferred stock at $0.01 par value per share have been authorized. No shares have been issued or are outstanding; accordingly, no information has been included in the Consolidated Statements of Stockholders’ Equity.

[2] Includes 116,238, 105,087 and 95,329 shares at December 31, 2021, 2020 and 2019, 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 2021, 2020 and 2019, we withheld 14,020, 10,319 and 7,635 shares, respectively, for taxes.(5) Includes the Retirement Savings Plan, DRIP and ATM equity issuances.