Future Policy Benefits (Undiscounted and Discounted) (Details) - USD ($) $ in Millions	Mar. 31, 2026	Mar. 31, 2025
Americas [Member] \| Life Insurance Product Line [Member]
Liability for Future Policy Benefit, Activity [Line Items]
Liability for Future Policy Benefit, Expected Future Gross Premium, Discounted, before Reinsurance	$ 85,394	$ 84,218
Liability for Future Policy Benefit, Expected Future Policy Benefit, Undiscounted, before Reinsurance	201,880	196,448
Liability For Future Policy Benefit Expected Future Policy Benefit Discounted Before Reinsurance	83,620	83,212
Liability for Future Policy Benefit, Expected Future Gross Premium, Undiscounted, before Reinsurance	195,188	183,915
Americas [Member] \| Insurance, Other
Liability for Future Policy Benefit, Activity [Line Items]
Liability for Future Policy Benefit, Expected Future Gross Premium, Discounted, before Reinsurance	3,258	1,666
Liability for Future Policy Benefit, Expected Future Policy Benefit, Undiscounted, before Reinsurance	26,202	22,679
Liability For Future Policy Benefit Expected Future Policy Benefit Discounted Before Reinsurance	13,169	10,940
Liability for Future Policy Benefit, Expected Future Gross Premium, Undiscounted, before Reinsurance	5,240	2,648
CANADA \| Life Insurance Product Line [Member]
Liability for Future Policy Benefit, Activity [Line Items]
Liability for Future Policy Benefit, Expected Future Gross Premium, Discounted, before Reinsurance	22,345	21,326
Liability for Future Policy Benefit, Expected Future Policy Benefit, Undiscounted, before Reinsurance	58,661	53,586
Liability For Future Policy Benefit Expected Future Policy Benefit Discounted Before Reinsurance	22,118	21,304
Liability for Future Policy Benefit, Expected Future Gross Premium, Undiscounted, before Reinsurance	57,804	52,094
CANADA \| Insurance, Other
Liability for Future Policy Benefit, Activity [Line Items]
Liability for Future Policy Benefit, Expected Future Gross Premium, Discounted, before Reinsurance	3,506	3,768
Liability for Future Policy Benefit, Expected Future Policy Benefit, Undiscounted, before Reinsurance	17,277	17,252
Liability For Future Policy Benefit Expected Future Policy Benefit Discounted Before Reinsurance	7,712	7,993
Liability for Future Policy Benefit, Expected Future Gross Premium, Undiscounted, before Reinsurance	5,344	5,689
EMEA [Member] \| Life Insurance Product Line [Member]
Liability for Future Policy Benefit, Activity [Line Items]
Liability for Future Policy Benefit, Expected Future Gross Premium, Discounted, before Reinsurance	17,060	15,240
Liability for Future Policy Benefit, Expected Future Policy Benefit, Undiscounted, before Reinsurance	32,795	28,718
Liability For Future Policy Benefit Expected Future Policy Benefit Discounted Before Reinsurance	16,734	14,829
Liability for Future Policy Benefit, Expected Future Gross Premium, Undiscounted, before Reinsurance	32,244	28,701
EMEA [Member] \| Insurance, Other
Liability for Future Policy Benefit, Activity [Line Items]
Liability for Future Policy Benefit, Expected Future Gross Premium, Discounted, before Reinsurance	77,830	65,091
Liability for Future Policy Benefit, Expected Future Policy Benefit, Undiscounted, before Reinsurance	179,589	139,460
Liability For Future Policy Benefit Expected Future Policy Benefit Discounted Before Reinsurance	85,881	70,120
Liability for Future Policy Benefit, Expected Future Gross Premium, Undiscounted, before Reinsurance	165,527	129,865
Asia Pacific [Member] \| Life Insurance Product Line [Member]
Liability for Future Policy Benefit, Activity [Line Items]
Liability for Future Policy Benefit, Expected Future Gross Premium, Discounted, before Reinsurance	48,532	42,040
Liability for Future Policy Benefit, Expected Future Policy Benefit, Undiscounted, before Reinsurance	121,664	101,929
Liability For Future Policy Benefit Expected Future Policy Benefit Discounted Before Reinsurance	41,204	35,804
Liability for Future Policy Benefit, Expected Future Gross Premium, Undiscounted, before Reinsurance	127,336	104,940
Asia Pacific [Member] \| Insurance, Other
Liability for Future Policy Benefit, Activity [Line Items]
Liability for Future Policy Benefit, Expected Future Gross Premium, Discounted, before Reinsurance	3,776	3,707
Liability for Future Policy Benefit, Expected Future Policy Benefit, Undiscounted, before Reinsurance	43,292	27,778
Liability For Future Policy Benefit Expected Future Policy Benefit Discounted Before Reinsurance	18,107	14,570
Liability for Future Policy Benefit, Expected Future Gross Premium, Undiscounted, before Reinsurance	$ 5,957	$ 5,292

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Amount, before effect of reinsurance, of discounted balance for expected future gross premium component of liability for future policy benefit.

+ References

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Amount, before effect of reinsurance, of undiscounted balance for expected future gross premium component of liability for future policy benefit.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
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-URI https://asc.fasb.org/1943274/2147480081/944-40-50-6

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Amount, before effect of reinsurance, of undiscounted balance for expected future policy benefit and expense component of liability for future policy benefit.

+ References

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