Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Cash flows from operating activities:
Net earnings	$ 38,765	$ 33,277	$ 26,785
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization	9,291	8,559	8,130
Stock compensation expense	3,692	3,992	3,076
Shares issued under employee benefit plans	475	431	430
Deferred income tax expense	307	(669)	(1,216)
(Recovery of) provision for doubtful accounts	(27)	(225)	305
Foreign currency transaction loss (gain)	197	(25)	36
Gain on sale of a product line	0	(931)	0
Loss on impairment of assets	94	311	0
Other	(57)	0	(8)
Changes in assets and liabilities
Accounts receivable	(2,697)	(2,744)	862
Inventories	(3,009)	(1,863)	2,656
Prepaid expenses and other current assets	(339)	43	1,776
Accounts payable and accrued expenses	739	2,645	4,037
Income taxes	(2,924)	(4,091)	1,009
Customer deposits and other deferred revenue	40	0	0
Other	355	320	194
Net cash provided by operating activities	44,902	39,030	48,072
Cash flows from investing activities:
Proceeds from sale of a product line	0	1,125	0
Acquisition of a business	0	(4,661)	0
Capital expenditures	(6,612)	(7,557)	(3,429)
Proceeds from sale of property, plant and equipment	28	0	0
Intangible assets (acquired) disposed	(25)	44	(215)
Net cash used in investing activities	(6,609)	(11,049)	(3,644)
Cash flows from financing activities:
Proceeds from long-term debt	0	97	0
Principal payments on long-term debt	(3,557)	(1,458)	(2,844)
Proceeds from short-term obligations	0	0	701
Repayments of short-term obligations	0	0	(2,657)
Proceeds from stock options exercised and restricted shares purchased	4,451	4,343	2,988
Excess tax benefits from stock compensation	2,894	4,230	2,289
Dividends paid	(4,311)	(3,091)	(2,008)
Purchase of treasury stock	(109)	(937)	0
Net cash (used in) provided by financing activities	(632)	3,184	(1,531)
Effect of exchange rate changes on cash	(133)	(344)	113
Increase in cash and cash equivalents	37,528	30,821	43,010
Cash and cash equivalents beginning of year	77,253	46,432	3,422
Cash and cash equivalents end of year	$ 114,781	$ 77,253	$ 46,432