Leases - Narrative (Details) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2019 USD ($)	Sep. 30, 2019 USD ($)
Lessee, Lease, Description [Line Items]
Remaining lease term		7 years
Lease renewal term	7 years	7 years
Increase (decrease) in operating lease assets	$ 6.1
Increase (decrease) in operating lease liabilities	$ 6.0
Weighted-average remaining lease term of operating leases	7 years	7 years
Weighted-average discount rate of operating leases (as a percent)	6.00%	6.00%
Operating lease payments	$ 0.5	$ 1.6
Operating lease expense	$ 0.5	1.6
Sublease income		$ 0.7