Summary of Significant Accounting Policies - Concentration of Revenue and Accounts Receivable (Details) - Customer concentration	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Revenue | Customer A
Concentration of Revenue and Accounts Receivable
Concentration risk percentage	55.00%	49.00%	57.00%	35.00%
Revenue | Customer B
Concentration of Revenue and Accounts Receivable
Concentration risk percentage	14.00%	12.00%	14.00%	19.00%
Revenue | Customer C
Concentration of Revenue and Accounts Receivable
Concentration risk percentage	12.00%			13.00%
Revenue | Customer D
Concentration of Revenue and Accounts Receivable
Concentration risk percentage		11.00%
Accounts Receivable | Customer A
Concentration of Revenue and Accounts Receivable
Concentration risk percentage			60.00%		69.00%
Accounts Receivable | Customer C
Concentration of Revenue and Accounts Receivable
Concentration risk percentage			22.00%
Accounts Receivable | Customer E
Concentration of Revenue and Accounts Receivable
Concentration risk percentage			11.00%
Accounts Receivable | Customer F
Concentration of Revenue and Accounts Receivable
Concentration risk percentage					14.00%