Discontinued Operations Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Apr. 01, 2017
Liabilities:
Accounts payable and accrued expenses	$ 58.8	$ 54.0
Other noncurrent liabilities	105.5	141.1
Liabilities subject to compromise			$ 8,416.7
Total liabilities classified as discontinued operations	$ 164.3	$ 195.1