Summary of Significant Accounting Policies (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012 businessunit	Dec. 31, 2011	Dec. 31, 2010
Foreign Currency Translation
Foreign currency transaction gains and losses	$ 12.4	$ 41.4	$ 27.5
Revenue Recognition
Number of business units in which sales incentive programs are significant	1
Revenues recognized under percentage of completion method	1,594.7	1,457.5	1,319.0
Costs and estimated earnings on uncompleted contracts
Costs incurred on uncompleted contracts	3,363.0	2,783.5
Estimated earnings to date	804.8	750.6
Aggregate costs incurred on uncompleted contracts and estimated earnings to date	4,167.8	3,534.1
Less: Billings to date	(4,066.7)	(3,514.4)
"Net costs and estimated earnings in excess of billings after the acquisition of Clyde Union (Holdings) S.A.R.L. (""Clyde Union"")"	101.1	19.7
Net costs and estimated earnings in excess of billings assumed in the acquisition of Clyde Union (Holdings) S.A.R.L. ("Clyde Union")	10.0	57.2
Net costs and estimated earnings in excess of billings	111.1	76.9
Billings in excess of costs and estimated earnings
Costs and estimated earnings in excess of billings	359.7	355.9
Billings in excess of costs and estimated earnings on uncompleted contracts	(248.6)	(279.0)
Net costs and estimated earnings in excess of billings	111.1	76.9
Billings in excess of costs and estimated earnings on uncompleted contracts reported as a component of accrued expenses	248.4	275.4
Billings in excess of costs and estimated earnings on uncompleted contracts reported as a component of other long-term liabilities	0.2	3.6
Research and Development Costs
Research and development expense	53.4	52.7	47.2
Property, plant and equipment
Depreciation expense	76.0	64.3	62.4
Interest capitalized	$ 0.5	$ 1.3	$ 3.9
Building
Property, plant and equipment
Useful lives of property, plant and equipment, high end of range (in years)	40.0
Machinery and equipment
Property, plant and equipment
Useful lives of property, plant and equipment, low end of range (in years)	3.0
Useful lives of property, plant and equipment, high end of range (in years)	15.0