Noncontrolling Interests in Consolidated Affiliates (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011	Dec. 31, 2010
Summary financial statistics - statement of operations and cash flows, consolidated affiliates
Sales	$ 754.4	$ 695.7
Income (loss) before taxes	92.1	79.5
Net income (loss)	61.3	54.0
Noncontrolling interests in net income (loss)	0.4	(0.2)
Summary financial statistics - balance sheet information, consolidated affiliates
Other current assets	86.5		93.0
Total assets	4,460.0		4,494.0
Total liabilities	4,200.6		4,326.5
Shareholders' equity	259.4	4.2	167.5	(68.8)
Noncontrolling interests in shareholders' equity	8.6		8.1
Joint ventures
Summary financial statistics - statement of operations and cash flows, consolidated affiliates
Sales	23.4	17.4
Income (loss) before taxes	1.8	(0.7)
Net income (loss)	1.6	(0.9)
Noncontrolling interests in net income (loss)	0.4	(0.2)
Summary financial statistics - balance sheet information, consolidated affiliates
Cash	6.7		6.7
Other current assets	36.4		34.7
Total assets	55.2		53.0
Total liabilities	31.4		30.3
Shareholders' equity	23.8		22.7
Noncontrolling interests in shareholders' equity	$ 8.6		$ 8.1