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Summary of Significant Accounting Policies - Narrative (Details) - USD ($) $ in Thousands | 12 Months Ended |  |  |
--- | --- | --- | --- | ---
Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2017 | Dec. 31, 2013 | Nov. 26, 2013
Concentration Risk [Line Items] |  |  |  |  |  |
Cash and cash equivalents | $ 16,629 | $ 34,640 | $ 7,435 |  | $ 1,890 |
Restricted cash held | 342 | 113 | 105 |  |  |
Cash held in escrow | 0 | 0 | 300 |  |  |
Inventory adjustments | 4,000 | 1,500 | 194 |  |  |
Operating loss carry-forwards | 10,600 |  |  |  |  |
Deferred tax assets, operating loss carry-forwards | 9,239 | 5,384 | $ 6,871 |  |  |
Impairment loss on equipment and software | $ 857 |  |  |  |  |
Antidilutive securities excluded from computation of earnings per share (number of shares) | 139,595 |  | 818,832 |  |  |
Advertising expense | $ 1,400 | $ 695 | $ 214 |  |  |
Customer concentration risk | Net sales |  |  |  |  |  |
Concentration Risk [Line Items] |  |  |  |  |  |
Concentration risk | 11.00% |  |  |  |  |
Customer concentration risk | Net sales | LED Lighting Solutions Global, LLC |  |  |  |  |  |
Concentration Risk [Line Items] |  |  |  |  |  |
Concentration risk |  | 59.00% | 64.00% |  |  |
Customer concentration risk | Net sales | Atlantic Diving Supply, Inc. |  |  |  |  |  |
Concentration Risk [Line Items] |  |  |  |  |  |
Concentration risk | 36.00% | 16.00% |  |  |  |
Customer concentration risk | Net sales | U.S. Navy |  |  |  |  |  |
Concentration Risk [Line Items] |  |  |  |  |  |
Concentration risk | 43.00% | 80.00% |  |  |  |
Customer concentration risk | Net sales | DFAS Columbus |  |  |  |  |  |
Concentration Risk [Line Items] |  |  |  |  |  |
Concentration risk |  |  | 10.00% |  |  |
Customer concentration risk | Accounts receivable |  |  |  |  |  |
Concentration Risk [Line Items] |  |  |  |  |  |
Concentration risk | 10.00% |  |  |  |  |
Customer concentration risk | Accounts receivable | Atlantic Diving Supply, Inc. |  |  |  |  |  |
Concentration Risk [Line Items] |  |  |  |  |  |
Concentration risk | 63.00% | 62.00% |  |  |  |
Minimum |  |  |  |  |  |
Concentration Risk [Line Items] |  |  |  |  |  |
Property and equipment, useful life | 2 years |  |  |  |  |
Warranty for finished goods, number of years | 1 year |  |  |  |  |
Maximum |  |  |  |  |  |
Concentration Risk [Line Items] |  |  |  |  |  |
Property and equipment, useful life | 15 years |  |  |  |  |
Warranty for finished goods, number of years | 10 years |  |  |  |  |
Scenario, forecast |  |  |  |  |  |
Concentration Risk [Line Items] |  |  |  |  |  |
Operating loss carry-forwards |  |  |  | $ 18,500 |  |
Domestic tax authority |  |  |  |  |  |
Concentration Risk [Line Items] |  |  |  |  |  |
Operating loss carry-forwards | $ 79,800 |  |  |  |  |
Deferred tax assets, operating loss carry-forwards | 25,400 |  |  |  |  |
Pool products |  |  |  |  |  |
Concentration Risk [Line Items] |  |  |  |  |  |
Cash held in escrow | $ 300 | $ 300 | $ 300 |  |  | $ 500

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