Leases (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019 USD ($)	Mar. 31, 2019 USD ($) ft²	Sep. 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 square feet | ft²		16,200
Renewal term (in years)		5 years
Lease, remaining square feet | ft²		33,400
Lease, option to terminate		P3Y
Lease liabilities	$ 3,735		$ 3,735
Right-of-use assets	3,431		3,431
Operating lease expense	600		1,800
Variable lease expense	$ 400		1,200
Operating lease payments			$ 2,500
Weighted-average remaining lease term	2 years		2 years
Weighted-average discount rate	11.20%		11.20%
Minimum
Leases
Term of lease (in years)	1 year		1 year
Maximum
Leases
Term of lease (in years)	6 years		6 years
ASC 842
Leases
Term of lease (in years)		3 years
Lease liabilities		$ 1,400		$ 4,700
Right-of-use assets		$ 1,400		$ 3,800