Retirement Plans - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($) plan	Dec. 31, 2019 USD ($)
Defined Benefit Plan Disclosure
Net loss to be recognize during the next fiscal period	$ 24
United States
Defined Benefit Plan Disclosure
Defined benefit plans, estimated future employer contributions in current fiscal year	$ 1,000
Pension Plan
Defined Benefit Plan Disclosure
Defined contribution plan number | plan	6
Pension Plan | United States
Defined Benefit Plan Disclosure
Number of retirement plans | plan	3
Number of defined benefit plans | plan	1
Defined contribution plan number | plan	2
Accrued pension obligation	$ 3,989	$ 3,449
Defined benefit plan, contributions	$ 300	550
Pension Plan | Canada
Defined Benefit Plan Disclosure
Defined contribution plan number | plan	2
Pension Plan | United Kingdom
Defined Benefit Plan Disclosure
Defined contribution plan number | plan	2
Defined benefit plans, estimated future employer contributions in current fiscal year	$ 337
Accrued pension obligation	2,290	1,811
Defined benefit plan, contributions	$ 337	314
Other Postretirement Benefits Plan
Defined Benefit Plan Disclosure
Service period	10 years
Other Postretirement Benefits Plan | Rail Technologies
Defined Benefit Plan Disclosure
Accrued pension obligation	$ 932	$ 840