Schedule II - Valuation and Qualifying Accounts - Valuation and Qualifying Accounts and Reserves (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018		Dec. 31, 2017
Doubtful Receivables [Member]
Balance at beginning of period	$ 96		$ 117
Charged (credited) to costs & expenses			71
Deductions	96	[1]	92	[2]
Balance at end of period			96
Discount Returns and Allowance [Member]
Balance at beginning of period	107		155
Charged (credited) to costs & expenses			(48)	[3]
Deductions	107	[1]
Balance at end of period			107
Doubtful Receivables & Discounts Returns and Allowances [Member]
Balance at beginning of period	203		272
Charged (credited) to costs & expenses			23
Deductions	203		92
Balance at end of period			$ 203

[1] Uncollectible receivables and reserves for discounts, returns, and allowances were disposed of in the Asset Sale on March 2, 2018

[2] Uncollectible receivables written-off, net of recoveries.

[3] Represents net increase (decrease) in the reserve.