Goodwill and Intangible Assets (Details) (USD $)	3 Months Ended		6 Months Ended		12 Months Ended						72 Months Ended	6 Months Ended			12 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2022	Jun. 30, 2011 Oil Field [Member]	Jun. 30, 2011 Power Transmission [Member]	Jun. 30, 2011 Non-compete agreements and trademarks [Member]	Dec. 31, 2010 Non-compete agreements and trademarks [Member]	Jun. 30, 2011 Customer relationships and contracts [Member]	Dec. 31, 2010 Customer relationships and contracts [Member]
Goodwill [Roll Forward]
Balance, beginning of period			$ 53,011,000							$ 53,011,000		$ 45,862,000	$ 7,149,000
Foreign currency translation			201,000									4,000	197,000
Balance, end of period	53,212,000		53,212,000									45,866,000	7,346,000
Intangible Assets [Abstract]
Gross carrying amount														2,550,000	2,550,000	15,183,000	15,183,000
Accumulated amortization														861,000	619,000	3,157,000	2,375,000
Net carrying amount														1,689,000	1,931,000	12,026,000	12,808,000
Weighted average amortization period (years)														6.30	6.30	10.0	10.0
Amortization expense of intangible assets	500,000	400,000	1,000,000	800,000
Future amortization expense of intangible assets [Abstract]
For the remainder of the year ended 12/31/11										1,000,000
For the year ended 12/31/12									1,885,000
For the year ended 12/31/13								1,858,000
For the year ended 12/31/14							1,707,000
For the year ended 12/31/15						1,670,000
For the year ended 12/31/16					1,613,000
Thereafter											$ 3,989,000