Leases - Lease Costs and Assumptions (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($)
Leases [Abstract]
Operating lease cost	$ 0.9
Short-term lease cost	0.5
Variable lease cost	0.4
Operating cash flows from operating leases	0.9
Right-of-use assets obtained in exchange for operating lease obligations	$ 0.8
Weighted average remaining lease term	8 years 4 months 24 days
Weighted average discount rate	4.80%