Segment Revenue and Operating Income (Loss) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013	Mar. 31, 2012
Segment Reporting Information [Line Items]
Revenue	$ 20,489	$ 17,407	$ 57,953	$ 55,664
Operating income (loss)	7,612	6,374	20,691	21,571
Operating Segments | Windows Division
Segment Reporting Information [Line Items]
Revenue	4,614	4,614	14,268	14,166
Operating income (loss)	2,369	2,960	7,849	9,054
Operating Segments | Server and Tools
Segment Reporting Information [Line Items]
Revenue	5,043	4,534	14,789	13,491
Operating income (loss)	1,981	1,692	5,855	5,214
Operating Segments | Online Services Division
Segment Reporting Information [Line Items]
Revenue	851	725	2,457	2,181
Operating income (loss)	(263)	(476)	(904)	(1,445)
Operating Segments | Microsoft Business Division
Segment Reporting Information [Line Items]
Revenue	6,130	5,838	18,304	17,752
Operating income (loss)	3,911	3,792	12,112	11,667
Operating Segments | Entertainment and Devices Division
Segment Reporting Information [Line Items]
Revenue	2,145	1,612	8,233	7,819
Operating income (loss)	(6)	(232)	944	642
Corporate and Reconciling Items
Segment Reporting Information [Line Items]
Revenue	1,706	84	(98)	255
Operating income (loss)	$ (380)	$ (1,362)	$ (5,165)	$ (3,561)