Retirement Plans - Schedule of Costs of Retirement Plans (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Defined Contribution Plan Disclosure
Expenses associated with contributions made	$ 564	$ 832	$ 574	$ 1,527
United States
Defined Contribution Plan Disclosure
Expenses associated with contributions made	433	680	295	1,230
Canada
Defined Contribution Plan Disclosure
Expenses associated with contributions made	30	34	69	72
United Kingdom
Defined Contribution Plan Disclosure
Expenses associated with contributions made	$ 101	$ 118	$ 210	$ 225