The Tax Identification Number (TIN), also known as an Employer Identification Number (EIN), is a unique 9-digit value assigned by the IRS.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation 12B
-Number 240
-Section 12
-Subsection b-2

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- Definition

Percentage of plan assets to benefit obligation of defined benefit plan.

+ References

No definition available.

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- Definition

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+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
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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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Pension and Postretirement Benefit Plans (Qualified Defined Benefit Multiemployer Plan) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jul. 01, 2019	Jul. 01, 2018	Jul. 01, 2017
Multiemployer Plans [Line Items]
Entity Tax Identification Number	42-6000149
Multiemployer Plans, Pension [Member]
Multiemployer Plans [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	$ 2	$ 1	$ 0
Defined Benefit Plan, Funded Percentage				108.59%	109.86%	111.30%
Federal Home Loan Bank of Des Moines [Member] \| Multiemployer Plans, Pension [Member]
Multiemployer Plans [Line Items]
Defined Benefit Plan, Funded Percentage				102.81%	107.53%	106.65%
Federal Home Loan Bank of Seattle [Member] \| Multiemployer Plans, Pension [Member]
Multiemployer Plans [Line Items]
Defined Benefit Plan, Funded Percentage				103.62%	106.00%	109.81%