Details of Selected Balance Sheet Accounts - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Inventory [Line Items]
Inventory write-down		$ 0	$ 0	$ 525
Cost of Sales | Canada
Inventory [Line Items]
Inventory write-down	$ 500