Commitments and Contingencies, Operating Lease (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($) ft²	Dec. 31, 2016 USD ($)
Operating Leased Assets [Line Items]
Rent expense	$ 567	$ 620
Minimum payments due under all non-cancelable lease agreements [Abstract]
2018	86
2019	15
2020	15
Total minimum lease and principal payments	116
Legal contingencies [Abstract]
Accrued liability related to back wages and related liquidated damages	30
Guarantees [Abstract]
Cost associated with guarantee obligations	0	0
Accrued guarantee obligations	$ 0	$ 0
Headquarters Office lease [Member]
Operating Leased Assets [Line Items]
Area of lease property | ft²	6,283
Lease expiration date	Mar. 31, 2018