Pension Plans Retirement Benefits and Savings Plans (details) - Future Payments $ in Millions	Dec. 31, 2016 USD ($)
Pension Plans [Member]
Estimated Future Benefit Payments
Benefits expected to be paid, 2017	$ 230
Benefits expected to be paid, 2018	240
Benefits expected to be paid, 2019	247
Benefits expected to be paid, 2020	253
Benefits expected to be paid, 2021	258
Benefits expected to be paid, 2022 through 2026	1,327
Postretirement Benefit Plans [Member]
Estimated Future Benefit Payments
Benefits expected to be paid, 2017	13
Benefits expected to be paid, 2018	14
Benefits expected to be paid, 2019	14
Benefits expected to be paid, 2020	14
Benefits expected to be paid, 2021	14
Benefits expected to be paid, 2022 through 2026	$ 71

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- Definition

Amount of benefits from a defined benefit plan expected to be paid in the five fiscal years after the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ 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=65897934&loc=d3e1928-114920

+ Details

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- Definition

Amount of benefits from a defined benefit plan expected to be paid in the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

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- Definition

Amount of benefits from a defined benefit plan expected to be paid in the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

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- Definition

Amount of benefits from a defined benefit plan expected to be paid in the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

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- Definition

Amount of benefits from a defined benefit plan expected to be paid in the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

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- Definition

Amount of benefits from a defined benefit plan expected to be paid in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

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