Consolidated Statements of Income (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Net sales:
Net sales:	$ 628,402	$ 603,593	$ 538,548
Cost of sales	484,890	468,508	421,634
Gross profit	143,512	135,085	116,914
Selling, general and administrative expenses	97,507	92,347	86,041
Gain on bargain purchase	0	(8,616)	0
Goodwill impairment	656	1,898	0
Income from operations	45,349	49,456	30,873
Interest expense	(1,620)	(2,422)	(3,664)
Interest income	234	247	1,533
Other income (expense), net	(517)	848	290
Income before income taxes	43,446	48,129	29,032
Provision for income taxes	14,543	15,442	7,915
Net income	28,903	32,687	21,117
Net income per common share:
Basic (in dollars per share)	$ 2.43	$ 2.76	$ 1.79
Diluted (in dollars per share)	$ 2.40	$ 2.73	$ 1.78
Average common shares:
Basic (in shares)	11,899,000	11,848,000	11,782,000
Diluted (in shares)	12,058,000	11,966,000	11,893,000
North American Industrial
Net sales:
Net sales:	263,353	229,594	196,783
Income from operations	19,313	24,649	8,513
North American Agricultural
Net sales:
Net sales:	200,467	203,993	181,349
Income from operations	18,319	16,644	10,073
European
Net sales:
Net sales:	164,582	170,006	160,416
Income from operations	$ 7,717	$ 8,163	$ 12,287