Restructuring - Restructuring Reserve Activity (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Restructuring accrual balances and related activity
Balance at beginning of period	$ 56.9	$ 54.0	$ 89.9
Liabilities incurred	50.2	65.0	49.4
Liabilities acquired			(8.2)
Liabilities paid/settled	(64.5)	(62.1)	(77.1)
Balance at end of period	$ 42.6	$ 56.9	$ 54.0