Long-term Debt (Detail) (USD $) In Millions, unless otherwise specified				9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended		12 Months Ended		9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended		12 Months Ended		9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended		12 Months Ended				9 Months Ended	12 Months Ended
	Mar. 31, 2013	Nov. 30, 2012	Jun. 30, 2012	Mar. 31, 2013 Notes 0.875 Percent Due September 27th 2013	Jun. 30, 2012 Notes 0.875 Percent Due September 27th 2013	Mar. 31, 2013 Notes 2.95 Percent Due June 1st 2014	Jun. 30, 2012 Notes 2.95 Percent Due June 1st 2014	Mar. 31, 2013 Notes 1.625 Percent Due September 25th 2015	Jun. 30, 2012 Notes 1.625 Percent Due September 25th 2015	Mar. 31, 2013 Notes 2.5 Percent Due February 8th 2016	Jun. 30, 2012 Notes 2.5 Percent Due February 8th 2016	Mar. 31, 2013 Notes 0.875 Percent Due November 15th 2017		Jun. 30, 2012 Notes 0.875 Percent Due November 15th 2017		Mar. 31, 2013 Notes 4.2 Percent Due June 1st 2019	Jun. 30, 2012 Notes 4.2 Percent Due June 1st 2019	Mar. 31, 2013 Notes 3.0 Percent Due October 1st 2020	Jun. 30, 2012 Notes 3.0 Percent Due October 1st 2020	Mar. 31, 2013 Notes 4.0 Percent Due February 8th 2021	Jun. 30, 2012 Notes 4.0 Percent Due February 8th 2021	Mar. 31, 2013 Notes 2.125 Percent Due November 15th 2022		Jun. 30, 2012 Notes 2.125 Percent Due November 15th 2022		Mar. 31, 2013 Notes 5.2 Percent Due June 1st 2039	Jun. 30, 2012 Notes 5.2 Percent Due June 1st 2039	Mar. 31, 2013 Notes 4.5 Percent Due October 1st 2040	Jun. 30, 2012 Notes 4.5 Percent Due October 1st 2040	Mar. 31, 2013 Notes 5.3 Percent Due February 8th 2041	Jun. 30, 2012 Notes 5.3 Percent Due February 8th 2041	Mar. 31, 2013 Notes 3.5 Percent Due November 15th 2042		Jun. 30, 2012 Notes 3.5 Percent Due November 15th 2042		Mar. 31, 2013 Notes, Total	Jun. 30, 2012 Notes, Total	Mar. 31, 2013 Convertible Debt	Jun. 30, 2012 Convertible Debt	Jun. 30, 2010 Convertible Debt
Debt Instrument [Line Items]
Debt maturity date				Sep. 27, 2013	Sep. 27, 2013	Jun. 01, 2014	Jun. 01, 2014	Sep. 25, 2015	Sep. 25, 2015	Feb. 08, 2016	Feb. 08, 2016	Nov. 15, 2017	[1]	Nov. 15, 2017	[1]	Jun. 01, 2019	Jun. 01, 2019	Oct. 01, 2020	Oct. 01, 2020	Feb. 08, 2021	Feb. 08, 2021	Nov. 15, 2022	[1]	Nov. 15, 2022	[1]	Jun. 01, 2039	Jun. 01, 2039	Oct. 01, 2040	Oct. 01, 2040	Feb. 08, 2041	Feb. 08, 2041	Nov. 15, 2042	[1]	Nov. 15, 2042	[1]			Jun. 15, 2013	Jun. 15, 2013
Face Value	$ 14,250	$ 2,250	$ 12,000	$ 1,000	$ 1,000	$ 2,000	$ 2,000	$ 1,750	$ 1,750	$ 750	$ 750	$ 600	[1]			$ 1,000	$ 1,000	$ 1,000	$ 1,000	$ 500	$ 500	$ 750	[1]			$ 750	$ 750	$ 1,000	$ 1,000	$ 1,000	$ 1,000	$ 900	[1]			$ 13,000	$ 10,750	$ 1,250	$ 1,250	$ 1,250
Stated Interest Rate				0.875%	0.875%	2.95%	2.95%	1.625%	1.625%	2.50%	2.50%	0.875%	[1]	0.875%	[1]	4.20%	4.20%	3.00%	3.00%	4.00%	4.00%	2.125%	[1]	2.125%	[1]	5.20%	5.20%	4.50%	4.50%	5.30%	5.30%	3.50%	[1]	3.50%	[1]			0.00%	0.00%
Effective Interest Rate				1.00%	1.00%	3.049%	3.049%	1.795%	1.795%	2.642%	2.642%	1.084%	[1]	1.084%	[1]	4.379%	4.379%	3.137%	3.137%	4.082%	4.082%	2.239%	[1]	2.239%	[1]	5.24%	5.24%	4.567%	4.567%	5.361%	5.361%	3.571%	[1]	3.571%	[1]			1.849%	1.849%

[1] In November 2012, we issued $2.25 billion of debt securities. The notes are senior unsecured obligations and rank equally with our other unsecured and unsubordinated debt outstanding.