Acquisitions and other Investments - narrative (Details) - USD ($) $ in Millions								3 Months Ended	12 Months Ended
	Mar. 31, 2023	Mar. 03, 2023	Jan. 03, 2023	Dec. 28, 2022	Aug. 31, 2022	Nov. 24, 2021	Oct. 29, 2021	Nov. 30, 2021	Aug. 31, 2023	Aug. 31, 2022	Aug. 31, 2021	Oct. 28, 2021
Business Acquisition [Line Items]
Goodwill, purchase accounting adjustments									$ 252
Gain on sale of equity method investment									1,855	$ 559	$ 321
Goodwill					$ 22,280				28,187	22,280	$ 12,421
VillageMD
Business Acquisition [Line Items]
Fair value of equity consideration			$ 1,750
Noncontrolling interest, ownership percentage by parent			53.00%
Debt instrument, fee amount, credit			$ 220
VillageMD | Line of Credit
Business Acquisition [Line Items]
Face amount			2,250
VillageMD | Line of Credit | Term loan
Business Acquisition [Line Items]
Face amount			1,750
VillageMD | Line of Credit | Credit facilities
Business Acquisition [Line Items]
Face amount			500
VillageMD | Cigna
Business Acquisition [Line Items]
Fair value of equity consideration			2,500
Summit Heath-CityMD
Business Acquisition [Line Items]
Cash consideration			7,000
Total purchase price			4,850
Fair value of equity consideration			1,971
Deferred consideration			100
Business combination, consideration transferred, employees			87
Summit debt paid at closing			1,900
Goodwill, purchase accounting adjustments									257
Tax deductible goodwill			433
Intangible assets			3,359
Goodwill			5,436
Summit Heath-CityMD | Partnership Interest
Business Acquisition [Line Items]
Fair value of equity consideration			2,050
Summit Heath-CityMD | Primary Care Provider Network
Business Acquisition [Line Items]
Intangible assets			$ 1,900
Useful life of capitalized software costs			15 years
Summit Heath-CityMD | Trade Names
Business Acquisition [Line Items]
Intangible assets			$ 1,500
Summit Heath-CityMD | Minimum | Trade Names
Business Acquisition [Line Items]
Useful life of capitalized software costs			11 years
Summit Heath-CityMD | Maximum | Trade Names
Business Acquisition [Line Items]
Useful life of capitalized software costs			15 years
VillageMD
Business Acquisition [Line Items]
Total purchase price						$ 5,200
Fair value of equity consideration						683
Goodwill, purchase accounting adjustments									125
Business combination, consideration transferred, gross						4,000
Business combination, consideration transferred, other						1,200
Business combination, consideration transferred to existing stockholders						2,900
Business acquisition, value of common stock shares acquired						1,900
Business combination, cash transferred for preferred units						1,100
Gain on sale of equity method investment								$ 1,597
Other comprehensive income (loss), reclassification adjustment from AOCI for investment transferred from available-for-sale to equity method, after tax								$ 577
Intangible assets						1,621
Goodwill						8,166
VillageMD | Primary Care Provider Network
Business Acquisition [Line Items]
Intangible assets						$ 1,200
Useful life of capitalized software costs						15 years
VillageMD | Trade Names
Business Acquisition [Line Items]
Intangible assets						$ 295
Useful life of capitalized software costs						13 years
VillageMD | Technology-Based Intangible Assets
Business Acquisition [Line Items]
Intangible assets						$ 76
Useful life of capitalized software costs						5 years
VillageMD | Minimum
Business Acquisition [Line Items]
Outstanding equity interest percentage						30.00%
VillageMD | Maximum
Business Acquisition [Line Items]
Outstanding equity interest percentage						63.00%
Shields Health Solutions
Business Acquisition [Line Items]
Cash consideration							$ 969
Total purchase price				$ 1,400
Fair value of equity consideration							$ 13
Goodwill, purchase accounting adjustments									72
Outstanding equity interest percentage				30.00%			70.00%					25.00%
Gain on sale of equity method investment										$ 402
Intangible assets							$ 1,060
Goodwill							1,529
Shields Health Solutions | Trade Names
Business Acquisition [Line Items]
Intangible assets							$ 47
Useful life of capitalized software costs							13 years
Shields Health Solutions | Technology-Based Intangible Assets
Business Acquisition [Line Items]
Intangible assets							$ 117
Useful life of capitalized software costs							5 years
Shields Health Solutions | Customer Relationships
Business Acquisition [Line Items]
Intangible assets							$ 896
Useful life of capitalized software costs							13 years
CareCentrix, Inc.
Business Acquisition [Line Items]
Cash consideration					327
Total purchase price	$ 378
Fair value of equity consideration					66
Business combination, consideration transferred, employees					$ 12
Goodwill, purchase accounting adjustments									56
Outstanding equity interest percentage	45.00%				55.00%					55.00%
Business combination, consideration transferred, gross					$ 339
Intangible assets					426					$ 426
Goodwill					509					509
CareCentrix, Inc. | Trade Names
Business Acquisition [Line Items]
Intangible assets					$ 93					$ 93
Useful life of capitalized software costs					13 years					13 years
CareCentrix, Inc. | Technology-Based Intangible Assets
Business Acquisition [Line Items]
Intangible assets					$ 86					$ 86
Useful life of capitalized software costs					5 years					5 years
CareCentrix, Inc. | Customer Relationships
Business Acquisition [Line Items]
Intangible assets					$ 247					$ 247
Useful life of capitalized software costs					13 years					13 years
Other Acquisitions
Business Acquisition [Line Items]
Total purchase price									324	$ 196
Starling MSO Holdings, LLC
Business Acquisition [Line Items]
Cash consideration		$ 284
Total purchase price		222
Fair value of equity consideration		$ 62
Intangible assets									128
Goodwill									$ 104