Shareholder Equity - Warrants (Details) - $ / shares	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019	Jun. 21, 2019	Mar. 23, 2018
Class of Warrant or Right [Line Items]
Exercise price per warrant (in usd per share)			$ 1.47	$ 1.20
Warrant Or Right Outstanding [Roll Forward]
Warrants outstanding, beginning balance (in shares)		9,257,632
Warrants Issued (in shares)		20,410,000
Warrants Exercised (in shares)	3,400,000	3,361,115
Warrants Expired (in shares)		0
Warrants outstanding, ending balance (in shares)	26,306,517	26,306,517
Warrants, Expiring June 2020
Class of Warrant or Right [Line Items]
Exercise price per warrant (in usd per share)	$ 1.47	$ 1.47
Warrant Or Right Outstanding [Roll Forward]
Warrants outstanding, beginning balance (in shares)		0
Warrants Issued (in shares)		20,410,000
Warrants Exercised (in shares)		0
Warrants Expired (in shares)		0
Warrants outstanding, ending balance (in shares)	20,410,000	20,410,000
Warrants, Expiring March 2023
Class of Warrant or Right [Line Items]
Exercise price per warrant (in usd per share)	$ 1.20	$ 1.20
Warrant Or Right Outstanding [Roll Forward]
Warrants outstanding, beginning balance (in shares)		7,210,945
Warrants Issued (in shares)		0
Warrants Exercised (in shares)		1,861,115
Warrants Expired (in shares)		0
Warrants outstanding, ending balance (in shares)	5,349,830	5,349,830
Warrants, Expiring November 2022
Class of Warrant or Right [Line Items]
Exercise price per warrant (in usd per share)	$ 0.80	$ 0.80
Warrant Or Right Outstanding [Roll Forward]
Warrants outstanding, beginning balance (in shares)		1,991,687
Warrants Issued (in shares)		0
Warrants Exercised (in shares)		1,500,000
Warrants Expired (in shares)		0
Warrants outstanding, ending balance (in shares)	491,687	491,687
Warrants, Expiring May 2025
Class of Warrant or Right [Line Items]
Exercise price per warrant (in usd per share)	$ 11.83	$ 11.83
Warrant Or Right Outstanding [Roll Forward]
Warrants outstanding, beginning balance (in shares)		27,500
Warrants Issued (in shares)		0
Warrants Exercised (in shares)		0
Warrants Expired (in shares)		0
Warrants outstanding, ending balance (in shares)	27,500	27,500
Warrants, Expiring November 2024
Class of Warrant or Right [Line Items]
Exercise price per warrant (in usd per share)	$ 11.04	$ 11.04
Warrant Or Right Outstanding [Roll Forward]
Warrants outstanding, beginning balance (in shares)		27,500
Warrants Issued (in shares)		0
Warrants Exercised (in shares)		0
Warrants Expired (in shares)		0
Warrants outstanding, ending balance (in shares)	27,500	27,500