Retirement Plans - Schedule of Costs of Retirement Plans (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Defined Contribution Plan Disclosure
Expenses associated with contributions made	$ 583	$ 564	$ 1,113	$ 574
United States
Defined Contribution Plan Disclosure
Expenses associated with contributions made	408	433	772	295
Canada
Defined Contribution Plan Disclosure
Expenses associated with contributions made	40	30	86	69
United Kingdom
Defined Contribution Plan Disclosure
Expenses associated with contributions made	$ 135	$ 101	$ 255	$ 210