Leases Leases - Lease Cost Additional Information (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Lease, Cost [Abstract]
Operating Lease Term				12 months
Operating Lease, Cost	[1]	$ 654	$ 698	$ 1,288	$ 1,805
Finance Lease, Right-of-Use Asset, Amortization		249	361	650	719
Finance Lease, Interest Expense		1	14	5	31
Lease, Cost		$ 904	$ 1,073	$ 1,943	$ 2,555

[1] (1) Includes short-term leases and variable lease costs, which are immaterial