Summary of Significant Accounting Policies - Concentration of Revenue and Accounts Receivable (Details) - Customer concentration	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Revenue | Customer A
Concentration of Revenue and Accounts Receivable
Concentration risk percentage	15.00%	17.00%	14.00%	22.00%
Revenue | Customer B
Concentration of Revenue and Accounts Receivable
Concentration risk percentage		10.00%	10.00%
Revenue | Customer C
Concentration of Revenue and Accounts Receivable
Concentration risk percentage		14.00%		15.00%
Revenue | Customer D
Concentration of Revenue and Accounts Receivable
Concentration risk percentage	67.00%	40.00%	58.00%	29.00%
Accounts Receivable | Customer C
Concentration of Revenue and Accounts Receivable
Concentration risk percentage					22.00%
Accounts Receivable | Customer D
Concentration of Revenue and Accounts Receivable
Concentration risk percentage			71.00%		55.00%
Accounts Receivable | Customer E
Concentration of Revenue and Accounts Receivable
Concentration risk percentage			13.00%