Pension and Other Employee Benefits (Schedule of Weighted-Average Net Periodic Benefit Cost Assumptions) (Details)	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Pension Plan [Member]
Defined Benefit Plans and PRB Plans [Line Items]
Discount rate	4.28%	3.68%	4.31%
Expected long-term rate of return on plan assets	7.38%	7.38%	7.39%
Pension Plan [Member] \| Minimum [Member]
Defined Benefit Plans and PRB Plans [Line Items]
Rate of compensation increase	2.00%	2.00%	2.00%
Pension Plan [Member] \| Maximum [Member]
Defined Benefit Plans and PRB Plans [Line Items]
Rate of compensation increase	7.00%	7.00%	7.00%
Pension Plan [Member] \| Weighted Average [Member]
Defined Benefit Plans and PRB Plans [Line Items]
Rate of compensation increase	4.43%	4.43%	4.43%
PRB [Member]
Defined Benefit Plans and PRB Plans [Line Items]
Discount rate	4.31%	3.72%	4.28%
Expected long-term rate of return on plan assets	6.25%	6.25%	6.25%
Health care trend rate	4.00%	4.00%	4.00%
PRB [Member] \| Minimum [Member]
Defined Benefit Plans and PRB Plans [Line Items]
Rate of compensation increase	2.00%	2.00%	2.00%
PRB [Member] \| Maximum [Member]
Defined Benefit Plans and PRB Plans [Line Items]
Rate of compensation increase	7.00%	7.00%	7.00%
PRB [Member] \| Weighted Average [Member]
Defined Benefit Plans and PRB Plans [Line Items]
Rate of compensation increase	4.50%	4.50%	4.50%

Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Health Care Trend Rate

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- Definition

Weighted average rate for present value of future retirement benefits cash flows, used to determine net periodic benefit cost of defined benefit plan.

+ 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 (k)(1)
-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920

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- Definition

Weighted average rate of return on plan assets, reflecting average rate of earnings expected on existing plan assets and expected contributions, used to determine net periodic benefit cost of defined benefit plan.

+ 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 (k)(3)
-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920

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- Definition

Weighted average rate of compensation increase used to determine net periodic benefit cost of defined benefit plan. Plan includes, but is not limited to, pay-related defined benefit plan.

+ 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 (k)(2)
-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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