Segment Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 28, 2012	Jun. 29, 2012	Mar. 30, 2012	Dec. 31, 2011	Sep. 30, 2011	Jul. 01, 2011	Apr. 01, 2011	Dec. 31, 2012 Segment	Dec. 31, 2011	Dec. 31, 2010
Number of operating segments									3
Revenues from transactions with other operating segments of same entity									$ 0	$ 0	$ 0
Net sales	1,603.1	1,500.6	1,478.1	1,432.5	1,369.1	1,517.8	1,532.2	1,447.6	6,014.3	5,866.7	4,864.9
Operating income									194.8	230.1	214.1
Capital expenditures									108.8	121.8	116.4
Depreciation expense									102.2	97.4	84.8
Assets	4,919.9				4,323.0				4,919.9	4,323.0	0
Long-lived assets	1,685.3				1,479.3				1,685.3	1,479.3
North America [Member]
Revenues from transactions with other operating segments of same entity									27.1	28.8	17.7
Net sales									2,340.2	2,120.2	1,785.0
Operating income									126.1	121.8	96.9
Capital expenditures									25.3	22.2	20.5
Depreciation expense									30.0	27.2	28.9
Assets	1,483.4				1,026.8				1,483.4	1,026.8	0
Europe and Mediterranean [Member]
Revenues from transactions with other operating segments of same entity									22.1	24.8	58.2
Net sales									1,678.9	1,735.7	1,498.6
Operating income									(13.0)	30.3	36.8
Capital expenditures									35.3	41.1	32.9
Depreciation expense									38.0	38.3	35.8
Assets	1,329.7				1,435.2				1,329.7	1,435.2	0
ROW [Member]
Revenues from transactions with other operating segments of same entity									95.5	38.1	42.2
Net sales									1,995.2	2,010.8	1,581.3
Operating income									81.7	78.0	80.4
Capital expenditures									48.2	58.5	63.0
Depreciation expense									34.2	31.9	20.1
Assets	2,106.8				1,861.0				2,106.8	1,861.0	0
Electric Utility [Member]
Net sales									1,959.6	1,851.3	1,501.4
Electrical Infrastructure [Member]
Net sales									1,611.5	1,708.3	1,345.7
Construction [Member]
Net sales									1,519.0	1,395.3	1,196.7
Communications [Member]
Net sales									651.2	655.3	593.7
Rod Mill Products [Member]
Net sales									273.0	256.5	227.4
UNITED STATES [Member]
Net sales									1,859.5	1,712.2	1,471.6
Long-lived assets	337.9				238.3				337.9	238.3
CANADA [Member]
Net sales									441.3	379.8	316.4
Long-lived assets	45.6				16.8				45.6	16.8
FRANCE [Member]
Net sales									494.9	506.0	445.2
Long-lived assets	78.3				78.3				78.3	78.3
BRAZIL [Member]
Net sales									440.1	478.7	317.1
Long-lived assets	121.3				120.9				121.3	120.9
SPAIN [Member]
Net sales									319.0	400.1	405.6
Long-lived assets	169.8				180.0				169.8	180.0
Others [Member]
Net sales									2,459.5	2,389.9	1,909.0
Long-lived assets	$ 932.4				$ 845.0				$ 932.4	$ 845.0