Retirement Plans - Schedule of Costs of Retirement Plans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Defined Contribution Plan Disclosure
Expenses associated with contributions made	$ 482	$ 734	$ 972	$ 2,174
United States
Defined Contribution Plan Disclosure
Expenses associated with contributions made	346	602	558	1,744
Canada
Defined Contribution Plan Disclosure
Expenses associated with contributions made	25	29	93	102
United Kingdom
Defined Contribution Plan Disclosure
Expenses associated with contributions made	$ 111	$ 103	$ 321	$ 328