Separation Costs Separation Accrual Rollforward (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2013		Dec. 31, 2012	Dec. 31, 2011
Separation Costs Accrual [Roll Forward]
Separation Cost Accrual - Beginning Balance							$ 0		$ 0
Separation Costs	13.0	[1]	0	[1]	0	[1]	0	[1]	13.0	[1]	0	0
Separation Cost Accrual											0
separation cost accrual ending period	5.7								5.7
Professional Fee [Member]
Separation Costs Accrual [Roll Forward]
Separation Costs									$ 7.3

[1] Separation costs of $13.0 million for the fourth quarter of 2013 related to the planned spinoff of the steel business.