Goodwill and Intangible Assets, Identifiable Intangible Table (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2012	Dec. 31, 2011
Identifiable intangible assets
Weighted average estimated useful life	24 years	24 years
Original cost	$ 39.7	$ 39.7
Accumulated amortization	(3.8)	(2.5)
Total	35.9	37.2
Customer relationships
Identifiable intangible assets
Weighted average estimated useful life	25 years	25 years
Original cost	38.5	38.5
Accumulated amortization	(2.8)	(1.7)
Total	35.7	36.8
Backlog
Identifiable intangible assets
Weighted average estimated useful life	2 years	2 years
Original cost	0.8	0.8
Accumulated amortization	(0.8)	(0.7)
Total	0	0.1
Trademark and trade name [Member]
Identifiable intangible assets
Weighted average estimated useful life	3 years	3 years
Original cost	0.4	0.4
Accumulated amortization	(0.2)	(0.1)
Total	$ 0.2	$ 0.3