Employee Benefit Plans - Expected Payments (Details) $ in Millions	Dec. 31, 2019 USD ($)
Postretirement Medical Plan
Defined Benefit Plan, Expected Future Benefit Payment [Abstract]
2020	$ 3
2021	3
2022	3
2023	4
2024	4
2025-2029	15
United States
Defined Benefit Plan, Expected Future Benefit Payment [Abstract]
2020	90
2021	93
2022	95
2023	98
2024	100
2025-2029	524
U.K. Plan
Defined Benefit Plan, Expected Future Benefit Payment [Abstract]
2020	42
2021	44
2022	46
2023	46
2024	49
2025-2029	$ 268

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- Definition

Amount of benefits for defined benefit plan expected to be paid in five fiscal years after fifth fiscal year following latest fiscal year.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920

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- Definition

Amount of benefits for defined benefit plan expected to be paid in next fiscal year following latest fiscal year.

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Amount of benefits for defined benefit plan expected to be paid in fifth fiscal year following latest fiscal year.

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Amount of benefits for defined benefit plan expected to be paid in fourth fiscal year following latest fiscal year.

+ References

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Amount of benefits for defined benefit plan expected to be paid in third fiscal year following latest fiscal year.

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Amount of benefits for defined benefit plan expected to be paid in second fiscal year following latest fiscal year.

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