Income Taxes - Components of Income Tax Provision (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current:
Canada	$ 706	$ (1,151)	$ (5,986)
Foreign	266	1,189	1,472
Total	972	38	(4,514)
Deferred:
Canada	(9,399)	(31,403)	(9,194)
Foreign	(2,314)	0	218
Total	(11,713)	(31,403)	(8,976)
Net income tax benefit	$ (10,741)	$ (31,365)	$ (13,490)