Summary of Significant Accounting Policies (Adjustments in Consolidated Statement of Operations) (Details) (USD $) In Millions, except Per Share data, 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
Cost of sales									$ 5,241.1		$ 4,310.9		$ 3,865.7
Operating income									248.0		222.4		179.9
Income tax provision									(42.5)		(47.2)		(32.7)
Net income including noncontrolling interest									85.2		76.9		64.5
Net income attributable to Company common shareholders	4.4	3.6	37.5	38.2	35.0	18.1	23.8	(7.8)	83.8	[1]	69.2	[1]	56.3	[1]
Earnings per common share - basic	$ 0.09	$ 0.07	$ 0.72	$ 0.73	$ 0.67	$ 0.35	$ 0.46	$ (0.15)	$ 1.61	[2]	$ 1.33	[2]	$ 1.08	[2]
Earnings per common share - assuming dilution	$ 0.09	$ 0.07	$ 0.68	$ 0.70	$ 0.66	$ 0.34	$ 0.45	$ (0.15)	$ 1.57		$ 1.31		$ 1.07
As Originally Reported [Member]
Cost of sales													3,787.9
Operating income													257.7
Income tax provision													(58.4)
Net income including noncontrolling interest													116.6
Net income attributable to Company common shareholders													108.4
Earnings per common share - basic													$ 2.08
Earnings per common share - assuming dilution													$ 2.06
Adjustment [Member]
Cost of sales													77.8
Operating income													(77.8)
Income tax provision													25.7
Net income including noncontrolling interest													(52.1)
Net income attributable to Company common shareholders													$ (52.1)
Earnings per common share - basic													$ (1.00)
Earnings per common share - assuming dilution													$ (0.99)

[1] Numerator

[2] Under the two class method, Earnings per share — basic reflects undistributed earnings per share for both common stock and unvested share-based payment awards (restricted stock).