Benefit Plans, Pension and Other Postretirement Benefit Liabilities in Consolidated Balance Sheets (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Total Pension and Other Postretirement Benefit Liabilities Included in Balance Sheets [Abstract]
Other assets	$ 1.4	$ 4.6
Accrued liabilities	(2.1)	(2.0)
Pension and other postretirement benefits	$ (94.8)	$ (99.8)