v3.19.2

Summary of significant accounting policies - Adoption of ASU 2016-02 (Details) $ in Thousands	Jan. 01, 2019 USD ($) lease	Jun. 30, 2019 USD ($)
Adoption of New Accounting Standards
Operating lease right-of use asset	$ 321	$ 243
Operating lease liabilities		236
Carrying value of debt		$ 0
Remaining lease term		23 months
Incremental borrowing rate		8.00%
Charlotte, NC
Adoption of New Accounting Standards
Remaining operating lease payments		$ 12
ASU 2016-02, Leases
Adoption of New Accounting Standards
Election of practical expedients package	true
ASU 2016-02, Leases | Charlotte, NC
Adoption of New Accounting Standards
Short-term lease commitment	true
Number of short-term operating leases | lease	1
ASU 2016-02, Leases | Adjustment
Adoption of New Accounting Standards
Operating lease right-of use asset	$ 300
Operating lease liabilities	$ 300

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