Goodwill by Segment Rollforward (Details) (USD $)	6 Months Ended			6 Months Ended							6 Months Ended					6 Months Ended					6 Months Ended					6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2013 Earn-out Arrangements [Member]		Jun. 30, 2012 Earn-out Arrangements [Member]		Jun. 30, 2013 Reportable Segment [Member] Communications [Member]	Jun. 30, 2012 Reportable Segment [Member] Communications [Member]	Dec. 31, 2011 Reportable Segment [Member] Communications [Member]	Jun. 30, 2012 Reportable Segment [Member] Communications [Member] Earn-out Arrangements [Member]		Jun. 30, 2013 Reportable Segment [Member] Electrical Transmission [Member]	Jun. 30, 2012 Reportable Segment [Member] Electrical Transmission [Member]	Dec. 31, 2011 Reportable Segment [Member] Electrical Transmission [Member]	Jun. 30, 2012 Reportable Segment [Member] Electrical Transmission [Member] Earn-out Arrangements [Member]		Jun. 30, 2013 Reportable Segment [Member] Oil and Gas [Member]	Jun. 30, 2012 Reportable Segment [Member] Oil and Gas [Member]	Dec. 31, 2011 Reportable Segment [Member] Oil and Gas [Member]	Jun. 30, 2012 Reportable Segment [Member] Oil and Gas [Member] Earn-out Arrangements [Member]		Jun. 30, 2013 Reportable Segment [Member] Power Generation and Industrial [Member]	Jun. 30, 2012 Reportable Segment [Member] Power Generation and Industrial [Member]	Dec. 31, 2011 Reportable Segment [Member] Power Generation and Industrial [Member]	Jun. 30, 2012 Reportable Segment [Member] Power Generation and Industrial [Member] Earn-out Arrangements [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 826,110,000	$ 718,300,000	$ 714,800,000					$ 305,800,000	$ 258,000,000	$ 258,000,000			$ 129,500,000	$ 129,500,000	$ 129,500,000			$ 273,200,000	$ 213,200,000	$ 209,700,000			$ 117,600,000	$ 117,600,000	$ 117,600,000
Accruals of acquisition-related contingent consideration				0	[1]	3,500,000	[1]				0	[1]				0	[1]				3,500,000	[1]				0	[1]
Additions from new business combinations, goodwill	36,800,000							5,400,000					0					31,400,000					0
Currency translation adjustments, goodwill	(2,700,000)							0					0					(2,700,000)					0
Goodwill, ending balance	$ 860,207,000	$ 718,300,000	$ 714,800,000					$ 311,200,000	$ 258,000,000	$ 258,000,000			$ 129,500,000	$ 129,500,000	$ 129,500,000			$ 301,900,000	$ 213,200,000	$ 209,700,000			$ 117,600,000	$ 117,600,000	$ 117,600,000

[1] Represents contingent consideration for acquisitions prior to January 1, 2009, which is only accrued as earned, in accordance with U.S. GAAP.