Dispositions (Details) - Corporate and Other - ITF - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Gain (loss) on disposition of business	$ 0.0
Assets and liabilities included in held for sale
Property, plant, and equipment		$ 37.2
Accounts receivable and unbilled revenues		34.9
Materials, supplies, and inventories		18.4
Other current assets		2.6
Other long-term assets		3.7
Total assets		96.8
Accounts payable		12.9
Accrued payroll and benefits		2.4
Other current liabilities		4.5
Pension and OPEB obligations		1.2
Other long-term liabilities		0.6
Total liabilities		$ 21.6