Goodwill and Intangible Assets (Details) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Goodwill [Roll Forward]
Balance, beginning of period			$ 232,932,000
Goodwill acquired during the period			98,468,000
Foreign currency translation			7,226,000
Balance, end of period	338,626,000		338,626,000		232,932,000
Intangible Assets [Abstract]
Gross Carrying Amount	121,653,000		121,653,000		79,076,000
Accumulated Amortization	13,840,000		13,840,000		5,663,000
Net	107,813,000		107,813,000		73,413,000
Weighted Average Amortization Period (in years)			8.0		7.4
Amortization expense of intangible assets	3,800,000	500,000	10,900,000	1,600,000
Future amortization expense of intangible assets [Abstract]
For the remainder of the year ended 12/31/12			3,800,000
For the year ended 12/31/13			15,022,000
For the year ended 12/31/14			14,383,000
For the year ended 12/31/15			14,346,000
For the year ended 12/31/16			14,255,000
For the year ended 12/31/17			13,909,000
Thereafter			32,090,000
Non-compete agreements and trademarks [Member]
Intangible Assets [Abstract]
Gross Carrying Amount	10,201,000		10,201,000		6,258,000
Accumulated Amortization	1,768,000		1,768,000		1,091,000
Net	8,433,000		8,433,000		5,167,000
Weighted Average Amortization Period (in years)			6.5		5.1
Customer relationships and contracts [Member]
Intangible Assets [Abstract]
Gross Carrying Amount	111,452,000		111,452,000		72,818,000
Accumulated Amortization	12,072,000		12,072,000		4,572,000
Net	99,380,000		99,380,000		68,246,000
Weighted Average Amortization Period (in years)			9.5		9.6
Oilfield [Member]
Goodwill [Roll Forward]
Balance, beginning of period			225,770,000
Goodwill acquired during the period			98,468,000
Foreign currency translation			7,244,000
Balance, end of period	331,482,000		331,482,000
Power Transmission [Member]
Goodwill [Roll Forward]
Balance, beginning of period			7,162,000
Foreign currency translation			(18,000)
Balance, end of period	$ 7,144,000		$ 7,144,000