- Change in Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance, beginning	$ 16,367	$ 16,580
Other Comprehensive Income (Loss), Net of Tax	600	183
Balance, ending	16,532	16,965
Adjustments to Additional Paid in Capital, Other	(18)	(18)
Net Unrealized Gains (Losses) on Cash Flow Hedges
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance, beginning	(115)	(220)
Other comprehensive income (loss) before reclassifications	312	10
Amounts reclassified from AOCI	14	14
Balance, ending	211	(196)
Net Unrealized Gains (Losses) on Securities
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance, beginning	(93)	(373)
Other comprehensive income (loss) before reclassifications	292	148
Amounts reclassified from AOCI	(34)	4
Balance, ending	165	(221)
Foreign Currency Translation Adjustment
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance, beginning	0	0
Other comprehensive income (loss) before reclassifications	0	0
Amounts reclassified from AOCI	0	0
Balance, ending	0	0
Pension and Other Benefits Adjustment
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance, beginning	(654)	(730)
Other comprehensive income (loss) before reclassifications	0	0
Amounts reclassified from AOCI	16	6
Balance, ending	(638)	(724)
Accumulated Other
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance, beginning	0	(1)
Other comprehensive income (loss) before reclassifications	0	1
Amounts reclassified from AOCI	0	0
Balance, ending	0	0
Accumulated Other Comprehensive Income (Loss)
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance, beginning	(862)	(1,324)
Other comprehensive income (loss) before reclassifications	604	159
Other Comprehensive Income (Loss), Net of Tax	600	183
Amounts reclassified from AOCI	(4)	24
Balance, ending	$ (262)	$ (1,141)

Amount of other increase (decrease) in additional paid in capital (APIC).

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Amount after tax, before reclassification adjustments of other comprehensive income (loss).

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Amount after tax and reclassification adjustments of other comprehensive income (loss).

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Amount after tax of reclassification adjustments of other comprehensive income (loss).

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount of stockholders' equity (deficit), net of receivables from officers, directors, owners, and affiliates of the entity, attributable to both the parent and noncontrolling interests. Amount excludes temporary equity. Alternate caption for the concept is permanent equity.

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