Fair Value Measurements and Investments (Tables)

6 Months Ended

Mar. 31, 2013

Fair Value Disclosures [Abstract]

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis

Assets and Liabilities Measured at Fair Value on a Recurring Basis.

	Fair Value Measurements Using Inputs Considered as
	Level 1				Level 2				Level 3
	March 31, 2013		September 30, 2012		March 31, 2013		September 30, 2012		March 31, 2013		September 30, 2012
	(in millions)
Assets
Cash equivalents and restricted cash
Money market funds	$	477	$	5,676
Commercial paper					$	34	$	93
Investment securities, trading
Equity securities	72		66
Investment securities, available-for-sale
U.S. government-sponsored debt securities					2,737		2,821
U.S. Treasury securities	1,075		1,066
Equity securities	63		2
Corporate debt securities					362		63
Auction rate securities									$	7	$	7
Prepaid and other current assets
Foreign exchange derivative instruments					18		13
Total	$	1,687	$	6,810	$	3,151	$	2,990	$	7	$	7
Liabilities
Accrued liabilities
Visa Europe put option									$	145	$	145
Earn-out related to PlaySpan acquisition									—		12
Foreign exchange derivative instruments					$	17	$	11
Total	$	—	$	—	$	17	$	11	$	145	$	157