Commitments and Contingent Liabilities - Narratives (Details) $ in Thousands		12 Months Ended
	Mar. 13, 2019 USD ($)	Dec. 31, 2020 USD ($) company	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 04, 2020 USD ($)	Jun. 05, 2017 company
Product Liability Contingency
Legal fees		$ 0	$ 0	$ 43,400
Current portion of accrued settlement		8,000	8,000
Accrued legal settlement, non-current		24,000	$ 32,000
Number Of Companies Receiving General Notice Letter | company						140
Present value or proposed remedial work		1,100,000
Undiscovered remedial work		$ 1,700,000
Remedial work anticipated clean up period		13 years
Number of potentially responsible parties included in agreement | company		100
Accrual for environmental loss contingencies, obligations removed					$ 3,460
Uprr
Product Liability Contingency
Purchase commitment	$ 48,000
Annual commitment amount	8,000
Uprr
Product Liability Contingency
Litigation settlement amount		$ 32,000		50,000
Litigation settlement amount, current	2,000
Litigation settlement amount, non-current	48,000
Amounts reclassified to accrued settlement	$ 6,600
Legal fees		$ 43,400
Rail Technologies and Services
Product Liability Contingency
Product warranty expense				$ 611