Leases - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Lessee, Lease, Description [Line Items]
Operating lease expense	$ 7.3	$ 14.4
Operating lease liabilities in exchange for leased assets	1.5	2.9
Current operating lease liabilities
Lessee, Lease, Description [Line Items]
Operating lease expense	4.8	9.4
Noncurrent operating lease liabilities
Lessee, Lease, Description [Line Items]
Operating lease expense	$ 2.5	$ 5.0
Minimum
Lessee, Lease, Description [Line Items]
Lease, remaining lease term		1 year
Maximum
Lessee, Lease, Description [Line Items]
Lease, remaining lease term		8 years