Commitments and Contingent Liabilities - Narrative (Details) $ in Thousands		6 Months Ended
	Mar. 13, 2019 USD ($)	Jun. 30, 2021 USD ($) company	Dec. 31, 2020 USD ($)	Jun. 05, 2017 company
Product Liability Contingency
Litigation settlement amount		$ 30,000
Number of companies that received a general notice letter (company) | company				140
Present value of remedial work		1,100,000
Undiscovered remedial work		$ 1,700,000
Anticipated clean period		13 years
Number of potentially responsible parties included in agreement | company		100
Accrual for environmental loss		$ 2,524	$ 2,562
UPRR
Product Liability Contingency
Annual commitment amount	$ 8,000
UPRR
Product Liability Contingency
Litigation settlement amount	50,000
Litigation settlement amount, current	2,000
Litigation settlement amount, non-current	$ 48,000
Payment period	6 years