The Company, Accounting Pronouncements Recently Adopted (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018	Dec. 31, 2017
Assets and Liabilities, Lessee [Abstract]
Right-of-use assets	$ 1,485		$ 1,485		$ 0
Lease liabilities	1,506		1,506
Statement of Operations [Abstract]
Change in fair value of warrant liability loss	$ 0	$ 23	$ 0	$ 22
ASU 2016-02 [Member]
Assets and Liabilities, Lessee [Abstract]
Right-of-use assets					848
Lease liabilities					$ 848
ASU 2017-11 [Member]
Net Assets, Adjusted Balance [Abstract]
Cumulative accounting adjustment from adoption of new standard, net of tax						$ 67
Statement of Operations [Abstract]
Change in fair value of warrant liability loss		(23)		(22)
Balance Sheet [Abstract]
Fair value of warrant liability		25		25
ASU 2017-11 [Member] | Balances prior to Adoption of ASU 2017-11
Statement of Operations [Abstract]
Change in fair value of warrant liability loss		(263)		(222)
Balance Sheet [Abstract]
Fair value of warrant liability		289		289
ASU 2017-11 [Member] | Effect of Adoption Higher / (Lower) [Member]
Statement of Operations [Abstract]
Change in fair value of warrant liability loss		(240)		(200)
Balance Sheet [Abstract]
Fair value of warrant liability		$ (264)		$ (264)
ASU 2017-11 [Member] | Accumulated Deficit [Member]
Net Assets, Adjusted Balance [Abstract]
Cumulative accounting adjustment from adoption of new standard, net of tax						(2,547)
ASU 2017-11 [Member] | Additional Paid-In Capital [Member]
Net Assets, Adjusted Balance [Abstract]
Cumulative accounting adjustment from adoption of new standard, net of tax						$ 2,614