Segment and Geographic Information - Identifiable Assets (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Identifiable assets:
Total	$ 2,012.0	$ 1,898.4
United States
Identifiable assets:
Total	1,870.2	1,741.4
Canada
Identifiable assets:
Total	$ 141.8	$ 157.0