Postretirement Benefit Plans - Balance Sheet Items (Details) - Postretirement Benefit Plans [Member] - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Amounts recognized on the Consolidated Balance Sheets:
Current liabilities	$ (5.9)	$ (4.8)
Non-current liabilities	(108.7)	(122.6)
Total	$ (114.6)	$ (127.4)

Amount of liability, recognized in statement of financial position, for defined benefit pension and other postretirement plans, classified as noncurrent.

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant