Income Taxes - Reconciliation of Tax Positions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Canadian Federal
Reconciliation of the beginning and ending gross amounts of unrecognized tax positions
Unrecognized tax positions, beginning of year	$ 7,394	$ 4,268	$ 2,617
Gross increase — current period tax positions	6,482	3,126	1,651
Gross decrease — prior period tax positions	0	0	0
Gross increase — prior period tax positions	0	0	0
Expiration of statute of limitations	0	0	0
Unrecognized tax positions, end of year	13,876	7,394	4,268
Canadian Provincial
Reconciliation of the beginning and ending gross amounts of unrecognized tax positions
Unrecognized tax positions, beginning of year	9,652	8,648	8,010
Gross increase — current period tax positions	1,367	1,004	638
Gross decrease — prior period tax positions	(78)	0	0
Gross increase — prior period tax positions	0	0	0
Expiration of statute of limitations	0	0	0
Unrecognized tax positions, end of year	$ 10,941	$ 9,652	$ 8,648