Consolidated Statements of Cash Flows (Parenthetical) - Pension Benefits [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Employer contributions	$ 49.3	$ 143.4
U.S. [Member]
Employer contributions	$ 40.0	$ 135.0	$ 115.0