Concentrations - Concentration Risk Percentage (Details) - Customer Concentration Risk	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accounts Receivable
Concentration Risk [Line Items]
Concentration risk percentage	10.00%	10.00%
Accounts Receivable | Superior
Concentration Risk [Line Items]
Concentration risk percentage	31.00%	32.00%
Accounts Receivable | Best Buy
Concentration Risk [Line Items]
Concentration risk percentage	18.00%	22.00%
Accounts Receivable | GENCO
Concentration Risk [Line Items]
Concentration risk percentage	7.00%	10.00%
Sales Revenue, Net | Superior
Concentration Risk [Line Items]
Concentration risk percentage	30.00%	27.00%	17.00%
Sales Revenue, Net | Best Buy
Concentration Risk [Line Items]
Concentration risk percentage	9.00%	11.00%	20.00%
Sales Revenue, Net | GENCO
Concentration Risk [Line Items]
Concentration risk percentage	8.00%	11.00%	11.00%