Commitments and Contingencies (Details) $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended
	May 31, 2017	Jun. 30, 2017 USD ($) ft²	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($) ft²	Jun. 30, 2016 USD ($)
Product Warranty [Abstract]
Period of warranty				12 months
Change in warranty accrual [Roll Forward]
Beginning accrued warranty and related costs		$ 133	$ 431	$ 251	$ 497
Accruals for warranties issued		37	4	70	23
Adjustments related to pre-existing warranties including expirations and changes in estimates		(27)	(64)	(132)	(131)
Cost of warranty repair		(13)	(41)	(59)	(59)
Ending accrued warranty and related costs		$ 130	$ 330	$ 130	$ 330
Leases [Abstract]
Area of property under long-term operating lease (in square feet) | ft²		19,467		19,467
Additional years per lease option				3 years
Number of additional years to lease term	3 years
Term of royalty agreement				8 years
Aggregate amount payable towards royalty		$ 7,000		$ 7,000
Operating leases
Less than 1 year		221		221
1-3 years		351		351
4-5 years		92		92
More than 5 years		6		6
Total		670		670
Royalty agreement
Less than 1 year		575		575
1-3 years		287		287
Total		862		862
Total
Less than 1 year		796		796
1-3 years		638		638
4-5 years		92		92
More than 5 years		6		6
Total		$ 1,532		$ 1,532