Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Common stock at $1 par value	[1]	Capital in excess of par value	Reinvested earnings	Accumulated other comprehensive income (loss)	Employee benefit stock	Treasury stock
Balance at Dec. 31, 2012	$ 171,247	$ 20,441		$ 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		1,577
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
Balance at Dec. 31, 2013	196,563	20,504		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		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
Balance at Dec. 31, 2014	$ 214,331	20,523		48,353	189,365	(11,856)	(922)	(31,132)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock, par value (in dollars per share)	$ 1
Net earnings	$ 25,938				25,938
Pension and postretirement benefits, net of tax	(77)					(77)
Foreign currency translation adjustment	(847)					(847)
Cash dividends	(11,259)				(11,259)
Stock options exercised	1,641	28		1,546				67
Tax benefit on stock options and dividends	141			141
ESSOP transactions	396			242			154
Stock-based compensation	1,541			1,541
Issuance of treasury stock	470			355				115
Balance at Dec. 31, 2015	$ 232,275	$ 20,551		$ 52,178	$ 204,044	$ (12,780)	$ (768)	$ (30,950)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock, par value (in dollars per share)	$ 1

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