Fair Value of Financial Instruments - Schedule of Unobservable Inputs (Details)	3 Months Ended	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Fair Value Inputs, Equity, Quantitative Information [Line Items]
Discount rate for multiple valuation methodologies		20.00%
Income Approach Valuation Technique
Fair Value Inputs, Equity, Quantitative Information [Line Items]
Probability of redemption, private company	15.00%	12.50%	15.00%
Market Approach Valuation Technique
Fair Value Inputs, Equity, Quantitative Information [Line Items]
Probability of redemption, private company	15.00%	12.50%	15.00%
Probability Weighted Expected Return Method
Fair Value Inputs, Equity, Quantitative Information [Line Items]
Probability of redemption, initial public offering	52.50%	60.00%	52.50%
Probability of redemption, mergers and acquisitions	17.50%	15.00%	17.50%
Minimum
Fair Value Inputs, Equity, Quantitative Information [Line Items]
IPO revenue multiple	3.25	2.8	3.0
Forecasted revenue growth rate	28.00%	31.10%	28.00%
Discount rate for multiple valuation methodologies	20.00%		20.00%
Maximum
Fair Value Inputs, Equity, Quantitative Information [Line Items]
IPO revenue multiple	3.5	3.0	4.5
Forecasted revenue growth rate	40.00%	40.00%	40.90%
Discount rate for multiple valuation methodologies	25.00%		25.00%