Share Capital - Schedule of Information About PSU, DSU, RSU and Stock Option Activity (Details)	12 Months Ended
	Dec. 31, 2019 $ / shares shares
Number of Outstanding Stock Options
Balance, Beginning of period (in shares)	9,034,412
Granted (in shares)	2,943,990
Exercised (in shares)	0
Forfeited (in shares)	(1,213,170)
Expired (in shares)	(152,360)
Balance, End of period (in shares)	10,612,872
Exercisable, at end of period (in shares)	6,469,699
Vested, or expected to vest, at end of period through the life of the options (in shares)	10,445,530
Weighted Average Exercise Price /Stock Option ($)
Balance, Beginning of period (in USD per share) | $ / shares	$ 3.18
Granted (in USD per share) | $ / shares	2.04
Exercised (in USD per share) | $ / shares	0
Forfeited (in USD per share) | $ / shares	3.61
Expired (in USD per share) | $ / shares	5.27
Balance, End of period (in USD per share) | $ / shares	2.78
Exercisable, at end of period (in USD per share) | $ / shares	3.14
Vested, or expected to vest, at end of period through the life of the options (in USD per share) | $ / shares	$ 2.79
PSUs
Number of Outstanding Share Units
Balance, Beginning of period (in shares)	9,004,661
Granted (in shares)	6,355,214
Exercised (in shares)	(2,725,877)
Forfeited (in shares)	(1,262,631)
Expired (in shares)	0
Balance, End of period (in shares)	11,371,367
DSUs
Number of Outstanding Share Units
Balance, Beginning of period (in shares)	684,893
Granted (in shares)	567,101
Exercised (in shares)	0
Forfeited (in shares)	0
Expired (in shares)	0
Balance, End of period (in shares)	1,251,994