Leases - Lease Cost and Supplemental Cash Flow Information Related to Leases (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Leases [Abstract]
Total lease expense	$ 424		$ 1,272
Total lease expense		$ 579		$ 1,359
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from leases	$ 433		$ 1,548