Consolidated Statements of Shareholders' Equity (USD $) In Thousands, except Per Share data, unless otherwise specified	Total	Common stock at $1 par value		Capital in excess of par value	Reinvested earnings	Accumulated other comprehensive income (loss)	Employee benefit stock	Treasury stock
Balance at Dec. 31, 2010	$ 168,383	$ 21,259	[1]	$ 37,582	$ 156,101	$ (13,137)	$ (1,536)	$ (31,886)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	19,161				19,161
Employee benefit funded status adjustment, net of tax	(1,162)					(1,162)
Foreign currency translation adjustment	(267)					(267)
Cash dividends	(8,991)				(8,991)
Stock options exercised	235	33	[1]	202
Tax benefit on stock options and dividends	190			190
ESSOP transactions	104			53			51
Stock-based compensation	1,134			1,134
Issuance of treasury stock	494			284				210
Balance at Dec. 31, 2011	179,281	21,292	[1]	39,445	166,271	(14,566)	(1,485)	(31,676)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	28,032				28,032
Employee benefit funded status adjustment, net of tax	225					225
Foreign currency translation adjustment	393					393
Cash dividends	(9,497)				(9,497)
Stock options exercised	382	37	[1]	345
Tax benefit on stock options and dividends	297			297
ESSOP transactions	392			141			251
Stock-based compensation	1,266			1,266
Shares purchased and retired	(30,000)	(888)			(29,112)
Issuance of treasury stock	476			261				215
Common stock, par value (in dollars per share)	$ 1
Balance at Dec. 31, 2012	171,247	20,441	[1]	41,755	155,694	(13,948)	(1,234)	(31,461)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	24,617				24,617
Employee benefit funded status adjustment, net of tax	6,252					6,252
Foreign currency translation adjustment	172					172
Cash dividends	(9,993)				(9,993)
Stock options exercised	1,640	63	[1]	1,577
Tax benefit on stock options and dividends	382			382
ESSOP transactions	360			201			159
Stock-based compensation	1,388			1,388
Issuance of treasury stock	498			324				174
Common stock, par value (in dollars per share)	$ 1
Balance at Dec. 31, 2013	$ 196,563	$ 20,504	[1]	$ 45,627	$ 170,318	$ (7,524)	$ (1,075)	$ (31,287)

[1] Each common share of stock equals $1 par value; therefore, the number of common shares is the same as the dollar value.