EBP Key Assumptions (Details 3)	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Pension Benefits [Member]
Weighted average assumptions utilized to determine benefit obligations
Discount rate	2.45%	3.19%
Rate of compensation increase	3.76%	3.68%
Cash balance interest crediting rate	3.00%	3.50%
Weighted average assumptions utilized to determine net periodic benefit cost (credit)
Discount rate	3.08%	4.33%	3.67%
Expected long-term rate of return on plan assets	4.67%	5.26%	5.34%
Rate of compensation increase	3.68%	4.83%	4.93%
Cash balance interest crediting rate	3.50%	4.25%	4.25%
Other Postretirement Benefits [Member]
Weighted average assumptions utilized to determine benefit obligations
Discount rate	2.59%	3.27%
Weighted average assumptions utilized to determine net periodic benefit cost (credit)
Discount rate	3.27%	4.39%	3.71%
Expected long-term rate of return on plan assets	4.39%	5.01%	4.95%
Health care cost trend rate assumed for next fiscal year	7.00%
Direction and pattern of change for assumed health care cost trend rate	decreases
Ultimate health care cost trend rate	4.50%
Year that rate reaches ultimate trend rate	2027

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

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- Definition

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

+ References

+ Details

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- Definition

Weighted-average interest crediting rate used to determine benefit obligation of defined benefit plan. Plan includes, but is not limited to, cash balance and other defined benefit plans with promised interest crediting rate.

+ References

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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.

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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://www.xbrl.org/2003/role/disclosureRef
-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

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e2919-114920

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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

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- Definition

Weighted-average interest crediting rate used to determine net periodic benefit cost of defined benefit plan. Plan includes, but is not limited to, cash balance and other defined benefit plans with promised interest crediting rate.

+ References

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- Definition

Description of direction and pattern of change in assumed health care cost trend rate used to measure expected cost of benefits for defined benefit postretirement plan.

+ References

No definition available.

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- Definition

Assumed rate, for next fiscal year, based on annual change in cost of health care cost benefits used to measure expected cost of benefits covered by defined benefit postretirement plan. Factors include, but are not limited to, estimate of health care inflation, change in health care utilization or delivery pattern, technological advances, and change in health status of participant. Excludes factors for change in composition of plan population by age and dependency status.

+ References

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- Definition

Ultimate trend rate for health care cost for defined benefit postretirement plan.

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- References

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- Definition

Year ultimate health care cost trend rate is expected to be reached, in CCYY format.

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