Defined Benefit Plan Amortization Period.

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- Definition

Measurement date at which the weighted-average assumptions are used to determine the benefit obligations as of the end of each year.

+ References

No definition available.

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- References

No definition available.

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- Definition

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

+ References

+ Details

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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

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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- References

No definition available.

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- Definition

Amount of decrease in accumulated postretirement benefit obligation from one-percentage-point decrease in assumed health care cost trend rate.

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

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- Definition

Amount of decrease in service and interest cost components of net periodic postretirement benefit cost from one-percentage-point decrease in assumed health care cost trend rate.

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

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- Definition

Amount of increase in accumulated postretirement benefit obligation from one-percentage-point increase in assumed health care cost trend rate.

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

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- Definition

Amount of increase in service and interest cost components of net periodic postretirement benefit cost from one-percentage-point increase in assumed health care cost trend rate.

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

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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

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

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- Definition

Ultimate trend rate for health care cost for defined benefit postretirement 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 (l)
-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920

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- References

No definition available.

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- References

No definition available.

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- Definition

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

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

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Postretirement Health Care and Life Insurance Benefits Assumptions Used to Determine the Benefit Obligations and Periodic Benefit Cost (Details) $ in Millions		3 Months Ended	9 Months Ended	12 Months Ended
	Apr. 01, 2017	Apr. 01, 2017	Dec. 31, 2017	Dec. 31, 2020 years	Dec. 31, 2019 years	Dec. 31, 2018 USD ($)	Dec. 31, 2017 years	Dec. 31, 2016
Postretirement Health Care and Life Insurance Benefits
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Amortization Period \| years					5.9		10.3
Weighted-average assumptions used to determine benefit obligations
Discount rate					3.40%	4.35%
Measurement date	Apr. 01, 2017				Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Weighted-average assumptions used to determine net periodic benefit cost
Discount rate		4.15%	4.10%		4.35%	3.70%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets		0.00%	0.00%		5.00%	0.00%
Assumed health care cost trend rates, One percentage point increase
One Percentage-Point Increase Effect on total service and interest cost components						$ 2.5
One Percentage-Point Decrease Effect on total service and interest cost component						(2.3)
One Percentage-Point Increase Effect on total postretirement benefit obligation						57.3
One Percentage-Point Decrease Effect on total postretirement benefit obligation						$ (50.9)
Pre-Medicare
Assumed health care cost trend rate
Health care cost trend rate assumed for next year					6.75%	6.55%
Rate to which the cost trend is assumed to decline (the ultimate trend rate)					4.75%	4.75%
Year that the rate reaches the ultimate trend rate					2023		2023
Post-Medicare
Assumed health care cost trend rate
Health care cost trend rate assumed for next year					6.35%	6.15%
Rate to which the cost trend is assumed to decline (the ultimate trend rate)					4.75%	4.75%
Year that the rate reaches the ultimate trend rate					2023		2023
Scenario, Forecast \| Postretirement Health Care and Life Insurance Benefits
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Amortization Period \| years				4.9
Weighted-average assumptions used to determine net periodic benefit cost
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets				7.00%