Equity - Activity of Stock Options (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Number of Shares
Outstanding, beginning of period (in shares)	3,697,147
Granted (in shares)	0	0	0
Exercised (in shares)	(150,000)
Unvested options forfeited (in shares)	0
Vested options expired (in shares)	(661,813)
Outstanding, end of period (in shares)	2,885,334	3,697,147
Exercisable, end of period (in shares)	2,885,334
Weighted- Average Exercise Price
Outstanding, weighted average exercise price, beginning of period (in dollars per share)	$ 4.59
Granted, weighted average exercise price (in dollars per share)	0
Exercised, weighted average exercise price (in dollars per share)	0.72
Unvested options forfeited, weighted-average exercise price (in dollars per share)	0
Vested options expired, weighted-average exercise price (in dollars per share)	6.21
Outstanding, weighted average exercise price, end of period (in dollars per share)	4.42	$ 4.59
Exercisable, weighted average exercise price (in dollars per share)	$ 4.42
Stock options, additional disclosures
Outstanding options, weighted average remaining contractual term	2 years 8 months 23 days
Exercisable, weighted average remaining contractual term	2 years 8 months 23 days
Outstanding, aggregate intrinsic value	$ 9,191,697
Exercisable, aggregate intrinsic value	$ 9,191,697