Components of Unearned Revenue (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012		Jun. 30, 2012
Deferred Revenue Arrangement [Line Items]
Unearned revenue	$ 19,587		$ 20,059
Other
Deferred Revenue Arrangement [Line Items]
Unearned revenue	4,549	[1]	3,342	[1]
Other | Windows Deferral
Deferred Revenue Arrangement [Line Items]
Unearned revenue	1,700		540
Other | Office Deferral
Deferred Revenue Arrangement [Line Items]
Unearned revenue	$ 189

[1] Other as of September 30, 2012 includes $1.7 billion of unearned revenue associated with pre-sales of Windows 8 to original equipment manufacturers and retailers and sales of Windows 7 with an option to upgrade to Windows 8 ("the Windows Deferral") and $189 million primarily associated with revenue deferred on sales of the current version of the Microsoft Office system ("the Office Deferral"). Other as of June 30, 2012 includes $540 million of unearned revenue associated with the Windows Deferral.