Business Combinations - Schedule of Finite-Lived Intangible Assets Acquired as Part of Business Combination (Details) - USD ($) $ in Millions		1 Months Ended
	Mar. 29, 2024	Nov. 30, 2025	Sep. 30, 2025
Sana
Business Combination [Line Items]
Acquisition-related intangible assets		$ 126
Useful life of intangible assets		5 years
Sana \| Developed technology
Business Combination [Line Items]
Acquisition-related intangible assets		$ 97
Useful life of intangible assets		4 years
Sana \| Customer relationships
Business Combination [Line Items]
Acquisition-related intangible assets		$ 28
Useful life of intangible assets		8 years
Sana \| Trade name
Business Combination [Line Items]
Acquisition-related intangible assets		$ 1
Useful life of intangible assets		1 year
Paradox
Business Combination [Line Items]
Acquisition-related intangible assets			$ 253
Useful life of intangible assets			7 years
Paradox \| Developed technology
Business Combination [Line Items]
Acquisition-related intangible assets			$ 133
Useful life of intangible assets			5 years
Paradox \| Customer relationships
Business Combination [Line Items]
Acquisition-related intangible assets			$ 116
Useful life of intangible assets			9 years
Paradox \| Trade name
Business Combination [Line Items]
Acquisition-related intangible assets			$ 2
Useful life of intangible assets			1 year
Paradox \| Backlog
Business Combination [Line Items]
Acquisition-related intangible assets			$ 2
Useful life of intangible assets			3 years
HiredScore, Inc. (“HiredScore”)
Business Combination [Line Items]
Acquisition-related intangible assets	$ 135
Useful life of intangible assets	9 years
HiredScore, Inc. (“HiredScore”) \| Developed technology
Business Combination [Line Items]
Acquisition-related intangible assets	$ 111
Useful life of intangible assets	8 years
HiredScore, Inc. (“HiredScore”) \| Customer relationships
Business Combination [Line Items]
Acquisition-related intangible assets	$ 23
Useful life of intangible assets	14 years
HiredScore, Inc. (“HiredScore”) \| Trade name
Business Combination [Line Items]
Acquisition-related intangible assets	$ 1
Useful life of intangible assets	1 year

Workday, Inc. 10-K