The Company, Accounting Pronouncements Recently Adopted (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Assets and Liabilities, Lessee [Abstract]
Right-of-use assets	$ 755		$ 0
Lease liabilities	772
Statement of Operations [Abstract]
Change in fair value of warrant liability gain (loss)	$ 0	$ (1)
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 gain (loss)		1
Balance Sheet [Abstract]
Fair value of warrant liability		2
ASU 2017-11 [Member] | Balances prior to Adoption of ASU 2017-11
Statement of Operations [Abstract]
Change in fair value of warrant liability gain (loss)		40
Balance Sheet [Abstract]
Fair value of warrant liability		24
ASU 2017-11 [Member] | Effect of Adoption Higher / (Lower) [Member]
Statement of Operations [Abstract]
Change in fair value of warrant liability gain (loss)		(39)
Balance Sheet [Abstract]
Fair value of warrant liability		$ (22)
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