Major Customers - Narrative (Details) - Customer Concentration Risk - customer	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Revenues
Concentration Risk [Line Items]
Number of customers	2	2
Revenues | Customer No. 1
Concentration Risk [Line Items]
Concentration risk percentage	21.00%
Revenues | Customer No. 2
Concentration Risk [Line Items]
Concentration risk percentage	16.00%
Revenues | Customer No. 3
Concentration Risk [Line Items]
Concentration risk percentage		13.00%
Revenues | Customer No. 4
Concentration Risk [Line Items]
Concentration risk percentage		11.00%
Accounts Receivable | Customer No. 1
Concentration Risk [Line Items]
Concentration risk percentage	43.00%
Accounts Receivable | Customer No. 2
Concentration Risk [Line Items]
Concentration risk percentage	15.00%