Leases - Narrative (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Dec. 31, 2018	Dec. 30, 2018
Lessee, Lease, Description [Line Items]
Operating lease right-of-use assets	$ 66.9		$ 0.0
Operating lease current liabilities	20.3		0.0
Operating lease noncurrent liabilities	$ 49.3		$ 0.0
Accounting Standards Update 2016-02
Lessee, Lease, Description [Line Items]
Operating lease right-of-use assets		$ 74.1
Operating lease current liabilities		19.8
Operating lease noncurrent liabilities		$ 54.3
Minimum
Lessee, Lease, Description [Line Items]
Leases, remaining lease term (years)	1 year
Maximum
Lessee, Lease, Description [Line Items]
Leases, remaining lease term (years)	10 years