Business Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Business Segment Information [Abstract]
Number of operating business segments	2								2
Sales by segment [Abstract]
Total sales	$ 355,800	$ 340,300	$ 305,600	$ 279,500	$ 279,300	$ 231,700	$ 226,800	$ 194,400	$ 1,281,200	$ 932,135	$ 645,643
Gross sales									1,295,876	950,523	650,887
Inter-segment sales									(14,676)	(18,388)	(5,244)
Net sales	355,800	340,300	305,600	279,500	279,300	231,700	226,800	194,400	1,281,200	932,135	645,643
Earnings (loss) before income taxes [Abstract]
Total earnings (loss) before income taxes									125,955	105,469	67,445
Operating income (loss)									140,052	107,478	67,659
Other (expense) income, net									(14,097)	(2,009)	(214)
Earnings (loss) before income tax provision									125,955	105,469	67,445
Assets by segment [Abstract]
Segment Total assets	1,435,219				1,096,705				1,435,219	1,096,705	621,078
Capital expenditures by segment [Abstract]
Total capital expenditures									84,719	103,559	60,363
Depreciation/amortization by segment [Abstract]
Total depreciation/amortization									43,283	24,266	21,158
Revenues from External Customers and Long-Lived Assets [Line Items]
Total sales	355,800	340,300	305,600	279,500	279,300	231,700	226,800	194,400	1,281,200	932,135	645,643
Total P, P & E, net	401,673				346,430				401,673	346,430
United States [Member]
Sales by segment [Abstract]
Total sales									823,432	582,947	390,129
Net sales									823,432	582,947	390,129
Revenues from External Customers and Long-Lived Assets [Line Items]
Total sales									823,432	582,947	390,129
Total P, P & E, net	191,583				175,921				191,583	175,921
Europe [Member]
Sales by segment [Abstract]
Total sales									77,785	64,926	46,799
Net sales									77,785	64,926	46,799
Revenues from External Customers and Long-Lived Assets [Line Items]
Total sales									77,785	64,926	46,799
Total P, P & E, net	127,883				86,213				127,883	86,213
Canada [Member]
Sales by segment [Abstract]
Total sales									157,292	88,317	33,668
Net sales									157,292	88,317	33,668
Revenues from External Customers and Long-Lived Assets [Line Items]
Total sales									157,292	88,317	33,668
Total P, P & E, net	68,679				69,047				68,679	69,047
Latin America [Member]
Sales by segment [Abstract]
Total sales									115,148	100,287	103,390
Net sales									115,148	100,287	103,390
Revenues from External Customers and Long-Lived Assets [Line Items]
Total sales									115,148	100,287	103,390
Total P, P & E, net	13,237				14,884				13,237	14,884
Middle East/North Africa [Member]
Sales by segment [Abstract]
Total sales									86,472	69,703	43,913
Net sales									86,472	69,703	43,913
Revenues from External Customers and Long-Lived Assets [Line Items]
Total sales									86,472	69,703	43,913
Other [Member]
Sales by segment [Abstract]
Total sales									21,071	25,955	27,744
Net sales									21,071	25,955	27,744
Revenues from External Customers and Long-Lived Assets [Line Items]
Total sales									21,071	25,955	27,744
Total P, P & E, net	291				365				291	365
Continuing Operations [Member]
Assets by segment [Abstract]
Segment Total assets	1,435,219				1,096,705				1,435,219	1,096,705	620,442
Discontinued Operations [Member]
Assets by segment [Abstract]
Segment Total assets	0				0				0	0	636
Oil Field [Member]
Sales by segment [Abstract]
Total sales									1,075,612	736,488	477,867
Gross sales									1,083,152	743,545	479,732
Inter-segment sales									(7,540)	(7,057)	(1,865)
Net sales									1,075,612	736,488	477,867
Earnings (loss) before income taxes [Abstract]
Total earnings (loss) before income taxes									121,666	91,278
Operating income (loss)									135,745	93,058	57,749
Other (expense) income, net									(14,080)	(1,780)	(59)
Earnings (loss) before income tax provision									121,665	91,278	57,690
Assets by segment [Abstract]
Segment Total assets	1,162,071				869,519				1,162,071	869,519
Capital expenditures by segment [Abstract]
Total capital expenditures									71,579	83,871	43,938
Depreciation/amortization by segment [Abstract]
Total depreciation/amortization									33,361	16,548	13,484
Revenues from External Customers and Long-Lived Assets [Line Items]
Total sales									1,075,612	736,488	477,867
Power Transmission [Member]
Sales by segment [Abstract]
Total sales									205,588	195,647	167,776
Gross sales									212,724	206,978	171,155
Inter-segment sales									(7,136)	(11,331)	(3,379)
Net sales									205,588	195,647	167,776
Earnings (loss) before income taxes [Abstract]
Total earnings (loss) before income taxes									4,359	16,402
Operating income (loss)									4,315	16,298	10,911
Other (expense) income, net									45	104	26
Earnings (loss) before income tax provision									4,360	16,402	10,937
Assets by segment [Abstract]
Segment Total assets	165,136				153,429				165,136	153,429
Capital expenditures by segment [Abstract]
Total capital expenditures									10,062	5,995	8,445
Depreciation/amortization by segment [Abstract]
Total depreciation/amortization									6,436	6,893	6,752
Revenues from External Customers and Long-Lived Assets [Line Items]
Total sales									205,588	195,647	167,776
Corporate & Other [Member]
Sales by segment [Abstract]
Total sales									0	0	0
Gross sales									0	0	0
Inter-segment sales									0	0	0
Net sales									0	0	0
Earnings (loss) before income taxes [Abstract]
Total earnings (loss) before income taxes									(70)	(2,211)
Operating income (loss)									(8)	(1,878)	(1,001)
Other (expense) income, net									(62)	(333)	(181)
Earnings (loss) before income tax provision									(70)	(2,211)	(1,182)
Assets by segment [Abstract]
Segment Total assets	108,012				73,757				108,012	73,757
Capital expenditures by segment [Abstract]
Total capital expenditures									3,078	13,693	7,980
Depreciation/amortization by segment [Abstract]
Total depreciation/amortization									3,486	825	922
Revenues from External Customers and Long-Lived Assets [Line Items]
Total sales									$ 0	$ 0	$ 0