Leases - Impact of Operating Leases to Condensed Consolidated Financial Statements (Details) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2019 USD ($)	Sep. 30, 2019 USD ($)
Lease cost
Operating lease cost	$ 6.7	$ 19.0
Short-term lease cost	0.1	0.5
Variable lease cost	0.5	1.6
Total lease cost	$ 7.3	21.1
Other information
Operating cash outflows from operating leases		17.9
Right-of-use assets obtained in exchange for new operating lease liabilities		$ 2.0
Weighted-average remaining lease term - operating leases	4 years 10 months 24 days	4 years 10 months 24 days
Weighted-average discount rate - operating leases	4.20%	4.20%