Commitments and Contingencies (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Fees for excess emissions accrued			$ 6.4
Fees for excess emissions accrued, current			4.8
Fees for excess emissions accrued, long-term			1.6
Liabilities recognized for estimated environmental costs	39.6		39.6		32.8
Estimated environmental liabilities, years			10
Environmental expense	8.6	2.7	12.5	5.1
Receivables from insurance carriers related to environmental matters	2.0		2.0		2.2
Other accounts receivable	0.3		0.3		1.0
Long-term receivables	1.7		1.7		1.2
Unrecognized product overages	1.8		1.8
Maximum [Member]
Fees for excess emissions accrued			13.7
Minimum [Member]
Fees for excess emissions accrued			$ 6.4