Lease Disclosures Components of Lease Income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Leases [Abstract]
Minimum lease payments	$ 24.3	$ 25.0	$ 72.2	$ 76.2
Variable lease income	1.1	2.5	3.8	8.5
Total operating lease income	$ 25.4	$ 27.5	$ 76.0	$ 84.7