Carrying Amount of Goodwill (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
	Mar. 31, 2012	Mar. 31, 2012
Goodwill [Line Items]
Beginning Balance	$ 19,670	$ 12,581	[1]
Acquisitions	0	7,176
Other	28	(59)
Ending Balance	19,698	19,698
Windows & Windows Live Division
Goodwill [Line Items]
Beginning Balance	89	89
Acquisitions	0	0
Other	0	0
Ending Balance	89	89
Server and Tools
Goodwill [Line Items]
Beginning Balance	1,144	1,139
Acquisitions	0	7
Other	0	(2)
Ending Balance	1,144	1,144
Online Services Division
Goodwill [Line Items]
Beginning Balance	6,427	6,373
Acquisitions	0	54
Other	(11)	(11)
Ending Balance	6,416	6,416
Microsoft Business Division
Goodwill [Line Items]
Beginning Balance	6,927	4,167
Acquisitions	0	2,843
Other	36	(47)
Ending Balance	6,963	6,963
Entertainment and Devices Division
Goodwill [Line Items]
Beginning Balance	5,083	813
Acquisitions	0	4,272
Other	3	1
Ending Balance	$ 5,086	$ 5,086

[1] Derived from audited financial statements.