Employee Benefit Plans - Summary of Participants (Details)	Jan. 01, 2021 employee
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Active Employees	3,019
Retirees and Beneficiaries	11,659
Other	3,748
Total	18,426
Post-retirement Medical Plan
Defined Benefit Plan Disclosure [Line Items]
Active Employees	698
Retirees and Beneficiaries	847
Other	0
Total	1,545