Employee Retirement Benefits (Expected Future Benefit Payments For Qualified Plan And SERP) (Details) $ in Millions	Dec. 31, 2017 USD ($)
Retirement Benefits [Abstract]
Expected future benefit payments, 2018	$ 26
Expected future benefit payments, 2019	24
Expected future benefit payments, 2020	25
Expected future benefit payments, 2021	29
Expected future benefit payments, 2022	26
Expected future benefit payments, 2023 - 2027	$ 146

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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.

+ References

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- Definition

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

+ References

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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.

+ References

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

+ References

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