Components of Income Tax Provision (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Components Of Income Tax Expense Benefit [Line Items]
Current income tax provision (benefit)	$ 7,995	$ 9,325	$ 16,283
Deferred income tax provision (benefit)	(4,113)	(4,332)	(6,076)
Income Tax Provision (benefit)	3,882	4,993	10,207
CANADA
Components Of Income Tax Expense Benefit [Line Items]
Current income tax provision (benefit)	82	100	75
Deferred income tax provision (benefit)	(493)
UNITED STATES
Components Of Income Tax Expense Benefit [Line Items]
Current income tax provision (benefit)	1,324	1,109	8,095
Deferred income tax provision (benefit)	(1,256)	703	(2,272)
Other Countries
Components Of Income Tax Expense Benefit [Line Items]
Current income tax provision (benefit)	6,589	8,116	8,113
Deferred income tax provision (benefit)	$ (2,364)	$ (5,035)	$ (3,804)