Revenue Recognition - Contract Balances (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Change in Contract with Customer, Liability [Abstract]
Balance as of January 1	$ 227.4	$ 215.8
Revenue recognized	(69.1)	(79.5)
Revenue deferred	87.6	90.5
Acquired liabilities	1.5	0.6
Balance as of December 31	247.4	227.4
Change in Contract with Customer, Asset [Abstract]
Balance as of December 31	100.5	44.7
Change in contract assets	55.8	44.7
Balance as of January 1	44.7	0.0
Acquired assets	29.1
Revenue recognized and unbilled	$ 26.7	21.9
Adoption of ASC 606		$ 22.8