Leases - Lease Cash Flow and Supplemental Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$ 3.2	$ 3.1	$ 6.4	$ 6.2
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 1.8	$ 1.3	$ 4.3	$ 8.1