CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY AND COMPREHENSIVE INCOME (USD $) In Millions, unless otherwise specified	Total USD ($)	Common Stock Outstanding	Common Stock/APIC USD ($)	Treasury Stock USD ($)	Retained Earnings USD ($)	Accumulated Other Comprehensive Income (Loss) USD ($)	Total Viacom Stockholders' Equity USD ($)	Noncontrolling Interests USD ($)
Equity, at beginning of period at Sep. 30, 2010	$ 9,259		$ 8,347	$ (5,725)	$ 6,775	$ (114)	$ 9,283	$ (24)
Shares issued, at beginning of period at Sep. 30, 2010	608.5
Schedule of Capitalization Equity [Line Items]
Net earnings	1,001				986		986	15
Translation adjustments	83					81	81	2
Defined benefit pension plans	3					3	3
Other	(6)					(6)	(6)
Comprehensive income	1,081						1,064	17
Noncontrolling interests	(13)							(13)
Dividends declared	(182)				(182)		(182)
Purchase of treasury stock, value	(900)			(900)			(900)
Purchase of treasury stock, shares		(21.8)
Equity based compensation and other, value	88		88				88
Equity based compensation and other, shares		1.4
Equity, at end of period at Mar. 31, 2011	9,333		8,435	(6,625)	7,579	(36)	9,353	(20)
Shares issued, at end of period at Mar. 31, 2011		588.1
Equity, at beginning of period at Dec. 31, 2010	9,450		8,389	(6,125)	7,294	(86)	9,472	(22)
Shares issued, at beginning of period at Dec. 31, 2010		598.4
Schedule of Capitalization Equity [Line Items]
Net earnings	382				376		376	6
Translation adjustments	54					53	53	1
Defined benefit pension plans	2					2	2
Other	(5)					(5)	(5)
Comprehensive income	433						426	7
Noncontrolling interests	(5)							(5)
Dividends declared	(91)				(91)		(91)
Purchase of treasury stock, value	(500)			(500)			(500)
Purchase of treasury stock, shares		(11.4)
Equity based compensation and other, value	46		46				46
Equity based compensation and other, shares		1.1
Equity, at end of period at Mar. 31, 2011	9,333		8,435	(6,625)	7,579	(36)	9,353	(20)
Shares issued, at end of period at Mar. 31, 2011		588.1
Equity, at beginning of period at Sep. 30, 2011	8,633		8,615	(8,225)	8,418	(164)	8,644	(11)
Shares issued, at beginning of period at Sep. 30, 2011		558.3
Schedule of Capitalization Equity [Line Items]
Net earnings	818				797		797	21
Translation adjustments	(38)					(38)	(38)
Defined benefit pension plans	5					5	5
Other	4					4	4
Comprehensive income	789						768	21
Noncontrolling interests	(16)				5		5	(21)
Dividends declared	(273)				(273)		(273)
Purchase of treasury stock, value	(1,400)			(1,400)			(1,400)
Purchase of treasury stock, shares		(30.9)
Equity based compensation and other, value	59		59				59
Equity based compensation and other, shares		2.8
Equity, at end of period at Mar. 31, 2012	7,792		8,674	(9,625)	8,947	(193)	7,803	(11)
Shares issued, at end of period at Mar. 31, 2012		530.2
Equity, at beginning of period at Dec. 31, 2011			8,651	(8,925)	8,492	(204)	8,014	(11)
Shares issued, at beginning of period at Dec. 31, 2011		543.0
Schedule of Capitalization Equity [Line Items]
Net earnings	596				585		585	11
Translation adjustments	5					5	5
Defined benefit pension plans	3					3	3
Other	3					3	3
Comprehensive income	607						596	11
Noncontrolling interests	(6)				5		5	(11)
Dividends declared	(135)				(135)		(135)
Purchase of treasury stock, value	(700)			(700)			(700)
Purchase of treasury stock, shares		(14.7)
Equity based compensation and other, value	23		23				23
Equity based compensation and other, shares		1.9
Equity, at end of period at Mar. 31, 2012	$ 7,792		$ 8,674	$ (9,625)	$ 8,947	$ (193)	$ 7,803	$ (11)
Shares issued, at end of period at Mar. 31, 2012		530.2