Revenue from Lessor Arrangements and Contracts with Customers - Operating Lease and Service Revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Lease revenue:
Total revenue	$ 266.9	$ 296.3	$ 755.2	$ 849.3
VERIFI Sales Arrangements
Lease revenue:
Lease payments revenue	6.5	6.9	19.7	20.0
Variable lease revenue	2.1	1.7	5.6	5.0
Total lease revenue	8.6	8.6	25.3	25.0
Total service revenue	1.4	1.1	3.5	3.2
Total revenue	10.0	9.7	28.8	28.2
VERIFI Sales Arrangements | Fixed fee revenue
Lease revenue:
Total service revenue	0.0	0.0	0.1	0.1
VERIFI Sales Arrangements | Variable fee revenue
Lease revenue:
Total service revenue	$ 1.4	$ 1.1	$ 3.4	$ 3.1