Business Combinations (Estimated Fair Values of Assets Acquired and Liabilities Assumed) (Details) - USD ($) $ in Millions	Jan. 31, 2020	Oct. 31, 2019	Aug. 31, 2019	Jun. 30, 2019	May 31, 2019	Jan. 31, 2019	Aug. 31, 2018	May 31, 2018	Jan. 31, 2018
Business Acquisition [Line Items]
Contract asset	$ 449					$ 215
Goodwill	$ 25,134					$ 12,851			$ 7,314
Tableau Software, Inc.
Business Acquisition [Line Items]
Cash and cash equivalents			$ 644
Marketable securities			456
Accounts receivable			174
Contract asset			131
Operating lease right-of-use assets			361
Other assets			116
Acquired customer contract asset, current and noncurrent - intangible asset			56
Goodwill			10,806
Intangible assets			3,252
Accounts payable, accrued expenses and other liabilities, current and noncurrent			(257)
Unearned revenue			(242)
Deferred income taxes and income taxes payable			(320)
Operating lease liabilities			(332)
Net assets acquired			$ 14,845
ClickSoftware Technologies Ltd.
Business Acquisition [Line Items]
Cash and cash equivalents		$ 38
Accounts receivable		28
Other assets		33
Goodwill		1,132
Intangible assets		276
Accounts payable, accrued expenses and other liabilities, current and noncurrent		(55)
Unearned revenue		(40)
Deferred tax liability		(26)
Net assets acquired		$ 1,386
Salesforce.org
Business Acquisition [Line Items]
Cash and cash equivalents				$ 54
Deferred tax asset				59
Other current and noncurrent assets				46
Goodwill				164
Accounts payable, accrued expenses and other liabilities, current and noncurrent				(39)
Unearned revenue				(138)
Deferred income taxes and income taxes payable				(12)
Net assets acquired				$ 134
MapAnything, Inc.
Business Acquisition [Line Items]
Goodwill					$ 152
Intangible assets					$ 53
Datorama
Business Acquisition [Line Items]
Cash and cash equivalents							$ 21
Accounts receivable							9
Other current and noncurrent assets							3
Goodwill							586
Intangible assets							202
Accounts payable, accrued expenses and other liabilities, current and noncurrent							(10)
Unearned revenue							(4)
Deferred tax liability							(41)
Net assets acquired							$ 766
MuleSoft
Business Acquisition [Line Items]
Cash and cash equivalents								$ 57
Marketable securities								233
Accounts receivable								69
Contract asset								122
Acquired customer contract asset, current and noncurrent - intangible asset								61
Other current and noncurrent assets								29
Goodwill								4,816
Intangible assets								1,279
Accounts payable, accrued expenses and other liabilities, current and noncurrent								(40)
Unearned revenue								(57)
Deferred tax liability								(144)
Net assets acquired								$ 6,425