SIGNIFICANT ACCOUNTING POLICIES (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Inventories
Inventory valuation reserves	$ 2,040		$ 2,040		$ 337
Raw materials	13,358		13,358		16,079
Work-in-process	10,410		10,410		12,133
Finished goods	16,995		16,995		19,155
Supplies	945		945		953
Total inventory	41,708		41,708		48,320
Income Taxes
Foreign tax rate, low end of range (as a percent)			20.00%
Foreign tax rate, high end of range (as a percent)			35.00%
Financial statement benefit from change in federal tax laws			900
Basic earnings per share:
Net income attributable to DMC	3,562	3,754	7,216	8,834
Less income allocated to RSAs	(59)	(83)	(115)	(196)
Net income allocated to common stock for EPS calculation	3,503	3,671	7,101	8,638
Shares, basic	13,540,394	13,212,246	13,528,880	13,204,086
EPS, basic (in dollars per share)	$ 0.26	$ 0.28	$ 0.52	$ 0.65
Adjust shares for dilutives: Stock-based compensation plans	4,271	3,983	4,093	4,173
Diluted earnings per share:
Net income attributable to DMC	3,562	3,754	7,216	8,834
Less income allocated to RSAs	(59)	(83)	(115)	(196)
Net income allocated to common stock for EPS calculation	3,503	3,671	7,101	8,638
Shares, diluted	13,544,665	13,216,229	13,532,973	13,208,259
EPS, diluted (in dollars per share)	$ 0.26	$ 0.28	$ 0.52	$ 0.65
Oilfield Products
Segment information
Increase in inventory reserves	1,245
Increase in inventory reserves, net of tax	$ 895
Increase in inventory reserves, effect on basic earnings per share	$ (0.06)
Increase in inventory reserves, effect on diluted earnings per share	$ (0.06)