Employee Benefit Plans - Expected Benefit Payments (Details) $ in Millions	Dec. 31, 2017 USD ($)
Pension Benefits
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity
2018	$ 1,170
2019	1,177
2020	1,201
2021	1,220
2022	1,238
2023-2027	6,351
Other Postretirement and Postemployment Benefits
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity
2018	284
2019	291
2020	296
2021	297
2022	296
2023-2027	$ 1,417

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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://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=82843861&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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- Definition

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.

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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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