Commitments and Contingencies - Concentration Risk (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015
Concentration Risk [Line Items]
Percentage of cash and cash equivalents held with FDIC participating banks	94.00%
Cash and cash equivalents	$ 104,295	$ 111,292	$ 134,563	$ 145,726
Customer A | Customer Concentration Risk | Revenue
Concentration Risk [Line Items]
Concentration risk	17.10%	12.90%
Customer B | Customer Concentration Risk | Revenue
Concentration Risk [Line Items]
Concentration risk	11.20%
Customer B | Customer Concentration Risk | Accounts Receivable | Customer Receivable
Concentration Risk [Line Items]
Concentration risk	19.20%
Customer C | Customer Concentration Risk | Revenue
Concentration Risk [Line Items]
Concentration risk		18.30%
Customer D | Customer Concentration Risk | Revenue
Concentration Risk [Line Items]
Concentration risk		14.20%
Customer D | Customer Concentration Risk | Accounts Receivable | Customer Receivable
Concentration Risk [Line Items]
Concentration risk	9.60%
Customer E | Customer Concentration Risk | Revenue
Concentration Risk [Line Items]
Concentration risk		11.40%
Customer F | Customer Concentration Risk | Accounts Receivable | Customer Receivable
Concentration Risk [Line Items]
Concentration risk	10.40%
Customer G | Customer Concentration Risk | Accounts Receivable | Customer Receivable
Concentration Risk [Line Items]
Concentration risk			14.30%