Unearned Revenue by Segment (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Jun. 30, 2012
Deferred Revenue Arrangement [Line Items]
Unearned revenue	$ 19,587	$ 20,059
Windows & Windows Live Division
Deferred Revenue Arrangement [Line Items]
Unearned revenue	3,439	2,444
Server and Tools
Deferred Revenue Arrangement [Line Items]
Unearned revenue	6,654	7,445
Microsoft Business Division
Deferred Revenue Arrangement [Line Items]
Unearned revenue	8,266	9,015
Other segments
Deferred Revenue Arrangement [Line Items]
Unearned revenue	$ 1,228	$ 1,155

Amount of deferred revenue as of balance sheet date. Deferred revenue represents collections of cash or other assets related to a revenue producing activity for which revenue has not yet been recognized. Generally, an entity records deferred revenue when it receives consideration from a customer before achieving certain criteria that must be met for revenue to be recognized in conformity with GAAP.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 605

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SAB TOPIC 13.A.4(a).Q1 Response)

-URI http://asc.fasb.org/extlink&oid=6600647&loc=d3e214044-122780

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 13

-Section A

Name:	us-gaap_DeferredRevenue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant