Benefit Plans - Schedule of Pre-tax Amounts recognized in AOCI (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Qualified Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Prior service credit (cost)	$ (65)	$ (90)
Net actuarial gain (loss)	194	(858)
Net amount recognized	129	(948)
Nonqualified Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Prior service credit (cost)	58	77
Net actuarial gain (loss)	(274)	(263)
Net amount recognized	$ (216)	$ (186)

Amount, before tax, of accumulated other comprehensive (income) loss for defined benefit plan, that has not been recognized in net periodic benefit cost (credit).

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Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
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- Definition

Amount, before tax, of accumulated other comprehensive income (loss) for gain (loss) of defined benefit plan, that has not been recognized in net periodic benefit (cost) credit.

+ 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 (j)
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section 45
-Paragraph 14A
-URI http://asc.fasb.org/extlink&oid=124509347&loc=SL7669686-108580

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- Definition

Amount, before tax, of accumulated other comprehensive (income) loss for cost (credit) of benefit change attributable to participants' prior service from plan amendment or plan initiation of defined benefit plan, that has not been recognized in net periodic benefit cost (credit).

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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.

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