Accounting for Shared-based Payments - Schedule of Stock Option Activity (Details) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended	82 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015	Sep. 30, 2016
Weighted Average Remaining Contractual Term
Stock based compensation expense	$ 4,585,000	$ (69,000)	$ 8,494,000	$ 7,724,000
Stock Options | $0.44-9.12
Number of Options
Balance outstanding, beginning of period (in shares)			20,953,375
Balance outstanding, end of period (in shares)	26,737,930		26,737,930		20,953,375	26,737,930
Exercisable at the end of the period (in shares)	11,470,357		11,470,357			11,470,357
Exercise Price Per Share
Exercise price, low end of the range (in dollars per share)			$ 0.44		$ 0.44
Exercise price, high end of the range (in dollars per share)			9.12		9.12
Weighted Average Exercise Price Per Share
Balance outstanding, beginning of period (in dollars per share)			3.86
Balance outstanding, end of period (in dollars per share)	$ 3.78		3.78		$ 3.86	$ 3.78
Exercisable at the end of the period (in dollars per share)	$ 3.84		$ 3.84			$ 3.84
Intrinsic Value
Intrinsic value of options outstanding	$ 0		$ 0		$ 42,438,000	$ 0
Intrinsic value of options exercisable, end of period	$ 23,281,000		$ 23,281,000			23,281,000
Weighted Average Remaining Contractual Term
Balance			7 years 2 months 5 days		7 years 1 month 24 days
Exercisable at the end of the period			6 years 7 days
Stock Options | $0.44-9.12 | Contingent vesting
Weighted Average Remaining Contractual Term
Grant date fair value						28,600,000
Stock based compensation expense						$ 0
Stock Options | $2.93-5.63
Number of Options
Granted (in shares)			6,403,000
Exercise Price Per Share
Exercise price, low end of the range (in dollars per share)			$ 2.93
Exercise price, high end of the range (in dollars per share)			5.63
Weighted Average Exercise Price Per Share
Granted (in dollars per share)			$ 3.75
Stock Options | 3.33
Number of Options
Exercised (in shares)			(66,685)
Exercise Price Per Share
Exercise price, low end of the range (in dollars per share)			$ 2.94
Exercise price, high end of the range (in dollars per share)			4.61
Weighted Average Exercise Price Per Share
Exercised (in dollars per share)			$ 3.18
Stock Options | $2.98-9.12
Number of Options
Forfeited (in shares)			(551,760)
Exercise Price Per Share
Exercise price, low end of the range (in dollars per share)			$ 2.98
Exercise price, high end of the range (in dollars per share)			9.12
Weighted Average Exercise Price Per Share
Forfeited (in dollars per share)			$ 5.99