Summary of Significant Accounting Policies - Schedule of Revenue and Accounts Receivable for Each Significant Customer (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Allowance for Trade Receivables
Accounts Receivable
Accounts receivable allowance	$ 0		$ 0		$ 0
Revenue | Customer Concentration Risk | Customer A
Accounts Receivable
Concentration risk percentage			20.00%
Revenue | Customer Concentration Risk | Customer A | Maximum
Accounts Receivable
Concentration risk percentage	10.00%	10.00%		10.00%
Revenue | Customer Concentration Risk | Customer B
Accounts Receivable
Concentration risk percentage	14.00%	17.00%	14.00%	14.00%
Revenue | Customer Concentration Risk | Customer C
Accounts Receivable
Concentration risk percentage		15.00%		16.00%
Revenue | Customer Concentration Risk | Customer C | Maximum
Accounts Receivable
Concentration risk percentage	10.00%		10.00%
Revenue | Customer Concentration Risk | Customer D
Accounts Receivable
Concentration risk percentage	19.00%		13.00%
Revenue | Customer Concentration Risk | Customer D | Maximum
Accounts Receivable
Concentration risk percentage		10.00%		10.00%
Revenue | Customer Concentration Risk | Customer E
Accounts Receivable
Concentration risk percentage				11.00%
Revenue | Customer Concentration Risk | Customer E | Maximum
Accounts Receivable
Concentration risk percentage	10.00%	10.00%	10.00%
Revenue | Customer Concentration Risk | Customer F | Maximum
Accounts Receivable
Concentration risk percentage	10.00%	10.00%	10.00%	10.00%
Accounts Receivable, net | Customer Concentration Risk | Customer A | Maximum
Accounts Receivable
Concentration risk percentage			10.00%		10.00%
Accounts Receivable, net | Customer Concentration Risk | Customer B | Maximum
Accounts Receivable
Concentration risk percentage			10.00%		10.00%
Accounts Receivable, net | Customer Concentration Risk | Customer C | Maximum
Accounts Receivable
Concentration risk percentage			10.00%		10.00%
Accounts Receivable, net | Customer Concentration Risk | Customer D
Accounts Receivable
Concentration risk percentage			17.00%		11.00%
Accounts Receivable, net | Customer Concentration Risk | Customer E
Accounts Receivable
Concentration risk percentage					10.00%
Accounts Receivable, net | Customer Concentration Risk | Customer E | Maximum
Accounts Receivable
Concentration risk percentage			10.00%
Accounts Receivable, net | Customer Concentration Risk | Customer F
Accounts Receivable
Concentration risk percentage					15.00%
Accounts Receivable, net | Customer Concentration Risk | Customer F | Maximum
Accounts Receivable
Concentration risk percentage			10.00%