Other Assets (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Goodwill [Roll Forward]
Beginning Balance	$ 3.0	$ 2.9
Exchange rate	0	0.1
Ending Balance	3.0	3.0
Intangible assets
Total intangible assets	36.9	39.8
Intangible assets, net	4.7	10.1
Deferred financing costs	80.5	76.4
Less: Accumulated amortization-deferred financing costs	(56.3)	(49.6)
Deferred financing costs, net	24.2	26.8
Fair value of derivative instruments	0	0
Goodwill — Europe	3.0	3.0
Equity in net assets of affiliates	1.4	5.1
Customer supply agreement(1)	37.6	39.9
Other	36.2	6.1
Total	107.1	91.0
Patents [Member]
Intangible assets
Total intangible assets	1.9	2.0
Less: Accumulated amortization-patents	(1.3)	(1.2)
Favorable Leasehold Interests [Member]
Intangible assets
Total intangible assets	6.3	9.7
Less: Accumulated amortization-patents	(3.1)	(4.8)
Customer relationships [Member]
Intangible assets
Total intangible assets	28.7	28.1
Less: Accumulated amortization-patents	$ (27.8)	$ (23.7)