Operating Leases - Lease Cost (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Lessee Disclosure [Abstract]
Weighted average lease term (in years)	5 years
Weighted average discount rate (as a percent)	5.50%
Lease liabilities from new right-of-use assets obtained during the year	$ 0
Cash paid on operating leases		$ 1,055