Leases (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($) ft²	Jun. 30, 2019 USD ($)	Jan. 01, 2019 USD ($)
Leases
Lessor, Operating Lease, Existence of Option to Extend [true false]		true
Lessor, Operating Lease, Existence of Option to Terminate [true false]		true
Lease to eliminate | ft²		16,200
lease to extend | ft²		33,400
lease to additional term		5 years
lease to termination term		3 years
Lease liabilities	$ 4,405		$ 4,405
Right-of-use assets	3,974		3,974
Lease term related to amendment		3 years
Operating lease expense	500		1,200
Variable lease expense	$ 300		700
Operating lease payments			$ 900
Weighted-average remaining lease term	2 years		2 years
Weighted-average discount rate	11.30%		11.30%
ASC 842
Leases
Lease liabilities		$ 1,400		$ 4,700
Right-of-use assets		$ 1,400		$ 3,800