Leases - Impact of Operating Leases to Condensed Consolidated Financial Statements (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Lease cost
Operating lease cost	$ 26.1
Short-term lease cost	0.5
Variable lease cost	2.5
Total lease cost	29.1
Other information
Operating cash outflows from operating leases	24.0
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 20.1
Weighted-average remaining lease term - operating leases	5 years 1 month 6 days
Weighted-average discount rate - operating leases	3.60%
Rent expense		$ 47.5	$ 47.1