Other Balance Sheet Accounts (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Other Current Liabilities
Environmental contingencies	$ 32.0	$ 32.5
Accrued compensation	30.5	49.6
Accrued interest	29.5	16.2
Deferred revenue	20.4	27.2
Pension liabilities included in other current liabilities	14.5	14.4
Income taxes payable	5.6	5.7
Other accrued liabilities	57.1	63.3
Total Other Current Liabilities	189.6	208.9
Other Liabilities, Noncurrent [Abstract]
Environmental contingencies	28.8	33.8
Liability to unconsolidated affiliate	27.0	27.0
Asset Retirement Obligation	9.2	10.2
Postretirement liability	7.1	7.2
Deferred Tax Liabilities, Net, Noncurrent	2.9	2.8
Other noncurrent liabilities	44.6	45.7
Other Liabilities, Noncurrent	$ 119.6	$ 126.7