Goodwill and Intangible Assets (Details) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Goodwill [Roll Forward]
Balance, beginning of period	$ 354,319,000
Correction of error	(9,162,000)
Adjustments for prior year acquisitions	26,000
Foreign currency translation	(10,915,000)
Balance, end of period	334,268,000		354,319,000
Intangible Assets [Abstract]
Gross Carrying Amount	122,331,000		122,331,000
Accumulated Amortization	25,151,000		17,870,000
Net Carrying Amount	97,180,000		104,461,000
Weighted Average Amortization Period (years)	7.6		7.6
Amortization expense of intangible assets	3,800,000	3,100,000
Amortization expense of intangible assets for the reminder of the fiscal year	11,200,000
Future amortization expense of intangible assets [Abstract]
For the year ended December 31, 2014	14,329,000
For the year ended December 31, 2015	14,262,000
For the year ended December 31, 2016	14,167,000
For the year ended December 31, 2017	13,807,000
For the year ended December 31, 2018	13,798,000
Thereafter	15,587,000
Non-compete agreements and trademarks [Member]
Intangible Assets [Abstract]
Gross Carrying Amount	10,281,000		10,281,000
Accumulated Amortization	2,665,000		2,082,000
Net Carrying Amount	7,616,000		8,199,000
Weighted Average Amortization Period (years)	5.7		5.7
Customer relationships and contracts [Member]
Intangible Assets [Abstract]
Gross Carrying Amount	112,050,000		112,050,000
Accumulated Amortization	22,486,000		15,788,000
Net Carrying Amount	89,564,000		96,262,000
Weighted Average Amortization Period (years)	9.4		9.4
Oilfield [Member]
Goodwill [Roll Forward]
Balance, beginning of period	347,199,000
Correction of error	(9,162,000)
Adjustments for prior year acquisitions	26,000
Foreign currency translation	(10,849,000)
Balance, end of period	327,214,000
Power Transmission [Member]
Goodwill [Roll Forward]
Balance, beginning of period	7,120,000
Correction of error	0
Adjustments for prior year acquisitions	0
Foreign currency translation	(66,000)
Balance, end of period	$ 7,054,000