CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - 6 months ended Mar. 31, 2016 - USD ($) shares in Millions, $ in Millions		Total		Additional Paid-in Capital	Accumulated Income	Accumulated Other Comprehensive Loss	Class A common stock Common Stock	Class B common stock Common Stock	Class C common stock Common Stock
Beginning Balance (in shares) at Sep. 30, 2015							1,950	245	20
Beginning Balance at Sep. 30, 2015		$ 29,842		$ 18,073	$ 11,843	$ (74)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		3,648	[1]		3,648
Other comprehensive loss, net of tax		(22)				(22)
Comprehensive income		3,626
Conversion of class C common stock upon sale into public market (in shares)							3		(1)
Issuance and vesting of restricted stock and performance-based shares (in shares)							2
Issuance and vesting of restricted stock and performance-based shares		0
Share-based compensation, net of forfeitures (Note 11) (in shares)	[2]						0
Share-based compensation, net of forfeitures (Note 11)		97		97
Restricted stock and performance-based shares settled in cash for taxes (shares)							(1)
Restricted stock and performance-based shares settled in cash for taxes		(85)		(85)
Excess tax benefit for share-based compensation		43		43
Cash proceeds from issuance of common stock under equity plans (in shares)							1
Cash proceeds from issuance of common stock under employee equity plans		49		49
Cash dividends declared and paid, at a quarterly amount of $0.14 per as-converted share (Note 9)		$ (676)			(676)
Repurchase of class A common stock (Note 9) (in shares)		(50)	[3]				(50)
Repurchase of class A common stock (Note 9)		$ (3,765)		(532)	(3,233)
Ending Balance (in shares) at Mar. 31, 2016							1,905	245	19
Ending Balance at Mar. 31, 2016		$ 29,131		$ 17,645	$ 11,582	$ (96)

[1] Net income is allocated based on proportional ownership on an as-converted basis. The weighted-average number of shares of as-converted class B common stock used in the income allocation was 405 million for the three and six months ended March 31, 2016 and 2015. The weighted-average number of shares of as-converted class C common stock used in the income allocation was 77 million and 78 million for the three and six months ended March 31, 2016, respectively, and 81 million and 84 million for the three and six months ended March 31, 2015, respectively.

[2] Decrease in class A common stock related to forfeitures of restricted stock awards is less than 1 million shares.

[3] All shares repurchased in the open market have been retired and constitute authorized but unissued shares.