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, 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
Pension and postretirement benefits, 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	391			140			251
Stock-based compensation	1,266			1,266
Shares purchased and retired	(30,000)	(888)	[1]		(29,112)
Issuance of treasury stock	477			262				215
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
Pension and postretirement benefits, 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)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	29,678				29,678
Pension and postretirement benefits, net of tax	(2,611)					(2,611)
Foreign currency translation adjustment	(1,721)					(1,721)
Cash dividends	(10,631)				(10,631)
Stock options exercised	730	19	[1]	711
Tax benefit on stock options and dividends	38			38
ESSOP transactions	367			214			153
Stock-based compensation	1,449			1,449
Issuance of treasury stock	469			314				155
Common stock, par value (in dollars per share)	$ 1
Balance at Dec. 31, 2014	$ 214,331	$ 20,523	[1]	$ 48,353	$ 189,365	$ (11,856)	$ (922)	$ (31,132)

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