Segment Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Revenues from transactions with other operating segments of same entity									$ 0	$ 0	$ 0
Net sales	1,369.1	1,517.8	1,532.2	1,447.6	1,357.8	1,200.5	1,208.6	1,098.0	5,866.7	4,864.9	4,385.2
Operating income									248.0	222.4	179.9
Capital expenditures									121.8	116.4	143.6
Depreciation expense									97.4	84.8	84.8
Assets	4,370.4				4,327.7				4,370.4	4,327.7
Long-lived assets	1,483.3				1,522.0				1,483.3	1,522.0
North America [Member]
Net sales									2,120.2	1,785.0	1,484.6
Operating income									121.8	96.9	19.8
Capital expenditures									22.2	20.5	28.8
Depreciation expense									27.2	28.9	29.2
Assets	791.4				866.7				791.4	866.7
Europe And Mediterranean [Member]
Revenues from transactions with other operating segments of same entity									24.8	58.2	64.6
Net sales									1,735.7	1,498.6	1,562.7
Operating income									30.3	36.8	70.2
Capital expenditures									41.1	32.9	78.3
Depreciation expense									38.3	35.8	34.9
Assets	1,435.2				1,476.0				1,435.2	1,476.0
ROW [Member]
Revenues from transactions with other operating segments of same entity									38.1	42.2	26.6
Net sales									2,010.8	1,581.3	1,337.9
Operating income									95.9	88.7	89.9
Capital expenditures									58.5	63.0	36.5
Depreciation expense									31.9	20.1	20.7
Assets	1,908.4				1,833.8				1,908.4	1,833.8
Corporate [Member]
Assets	235.4				151.2				235.4	151.2
Electric Utility [Member]
Net sales									1,851.3	1,501.4	1,494.4
Electrical Infrastructure [Member]
Net sales									1,708.3	1,345.7	1,095.2
Construction [Member]
Net sales									1,395.3	1,196.7	1,008.5
Communications [Member]
Net sales									655.3	593.7	626.1
Rod Mill Products [Member]
Net sales									256.5	227.4	161.0
UNITED STATES [Member]
Net sales									1,712.2	1,471.6	1,239.9
Long-lived assets	220.1				226.8				220.1	226.8
SPAIN [Member]
Net sales									400.1	405.6	453.2
Long-lived assets	180.0				194.7				180.0	194.7
Others [Member]
Net sales									3,754.4	2,987.7	2,692.1
Long-lived assets	$ 1,083.2				$ 1,100.5				$ 1,083.2	$ 1,100.5