Debt - Additional Information (Detail) (USD $)	1 Months Ended	12 Months Ended
	Jun. 30, 2010	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2010
Debt Instrument [Line Items]
Long-term debt		$ 11,900,000,000	$ 11,900,000,000
Long-term debt fair value		13,200,000,000	12,100,000,000
Unamortized discount		56,000,000	79,000,000
Principal amount of outstanding long-term debt		12,000,000,000	12,000,000,000
Proceeds from convertible debt offering	1,240,000,000
Current portion of long-term debt		1,231,000,000	0
Capped call options, cap price	37.16
Derivative asset		483,000,000	416,000,000
Cash paid for interest		344,000,000	197,000,000	145,000,000
Purchased Call Option
Debt Instrument [Line Items]
Derivative asset	40,000,000			40,000,000
Debt
Debt Instrument [Line Items]
Proceeds from convertible debt offering	1,180,000,000
Equity
Debt Instrument [Line Items]
Proceeds from convertible debt offering	58,000,000
Convertible Debt
Debt Instrument [Line Items]
Unamortized discount		19,000,000
Principal amount of outstanding long-term debt	1,250,000,000	1,250,000,000	1,250,000,000	1,250,000,000
Debt instrument maturity date		Jun. 15, 2013	Jun. 15, 2013
Principal amount of each convertible note	$ 1,000			$ 1,000
Shares of Microsoft common stock into which each $1,000 principal amount of notes may convert	29.94
Conversion price per share of convertible notes	$ 33.40			$ 33.40
Terms of conversion change date	Mar. 15, 2013