INCOME TAXES (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Current [Abstract]
Federal	$ 16,096	$ 14,329	$ 11,922
Foreign	1,441	1,287	1,700
State	131	1,906	1,425
Deferred [Abstract]
Federal	177	(803)	(1,181)
Foreign	127	183	53
State	1	(48)	(102)
Total income tax provision	17,973	16,854	13,817
Federal statutory rate (in hundredths)		35.00%
Income tax reconciliation [Abstract]
Income tax at Federal statutory rate	19,858	17,546	14,211
State income taxes, net of Federal income tax benefit	(207)	987	766
Other	(1,678)	(1,679)	(1,160)
Total income tax provision	17,973	16,854	13,817
Deferred tax assets [Abstract]
Inventories	396	388
Restricted stock and stock options	4,218	3,352
Other	773	774
Total deferred tax assets	5,387	4,514
Deferred tax liabilities [Abstract]
Customer list and goodwill amortization	2,952	3,313
Depreciation	6,471	4,855
Prepaid expense	574	642
Trade names and trademarks	157	171
Technology and trade secrets	176	192
Other	485	431
Total deferred tax liabilities	10,815	9,604
Net deferred tax liability	5,428	5,090
Decrease in retained earnings due to adoption of ASC 740-10	291
Unrecognized tax benefits [Roll Foward]
Balance, beginning of period	1,246	972	813
Increases for tax positions of prior years	397	97	73
Decreases for tax positions of prior years	(168)	(127)	(131)
Increases for tax positions related to current year	546	304	217
Balance, end of period	2,021	1,246	972
Interest and penalties	133	152	110
Accrued interest and penalties	$ 547	$ 414