Consolidated Statements of Stockholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Total ViacomCBS Stockholders’ Equity [Member]	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-In Capital [Member]	Treasury Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Noncontrolling Interest [Member]
Balance, beginning of year (shares) at Dec. 31, 2019				615
Balance, beginning of year at Dec. 31, 2019	$ 13,289	$ 13,207		$ 1	$ 29,590	$ (22,908)	$ 8,494	$ (1,970)	$ 82
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation activity (shares)				2
Stock-based compensation activity	90	90			90
Class B Common Stock purchased (shares)				(1)
Class B Common Stock purchased	(50)	(50)				(50)
Common stock dividends	(300)	(300)					(300)
Noncontrolling interests	308	(41)					(41)		349	[1]
Net earnings	1,245	997					997		248
Other comprehensive income (loss)	(32)	(29)						(29)	(3)
Balance, end of year (shares) at Jun. 30, 2020				616
Balance, end of year at Jun. 30, 2020	14,550	13,874		$ 1	29,680	(22,958)	9,150	(1,999)	676
Balance, beginning of year (shares) at Mar. 31, 2020				615
Balance, beginning of year at Mar. 31, 2020	13,521	13,449		$ 1	29,633	(22,958)	8,827	(2,054)	72
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation activity (shares)				1
Stock-based compensation activity	47	47			47
Common stock dividends	(150)	(150)					(150)
Noncontrolling interests	351	(8)					(8)		359	[1]
Net earnings	726	481					481		245
Other comprehensive income (loss)	55	55						55
Balance, end of year (shares) at Jun. 30, 2020				616
Balance, end of year at Jun. 30, 2020	14,550	13,874		$ 1	29,680	(22,958)	9,150	(1,999)	676
Balance, beginning of year (shares) at Dec. 31, 2020			0	617
Balance, beginning of year at Dec. 31, 2020	16,056	15,371	$ 0	$ 1	29,785	(22,958)	10,375	(1,832)	685
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation activity (shares)				9
Stock-based compensation activity	461	461			461
Stock issuance (in shares)			10	20
Stock issuances	2,655	2,655			2,655
Preferred stock dividends	(15)	(15)					(15)
Common stock dividends	(310)	(310)					(310)
Noncontrolling interests	(142)	10					10		(152)
Net earnings	1,972	1,947					1,947		25
Other comprehensive income (loss)	(21)	(21)						(21)
Balance, end of year (shares) at Jun. 30, 2021			10	646
Balance, end of year at Jun. 30, 2021	20,656	20,098	$ 0	$ 1	32,901	(22,958)	12,007	(1,853)	558
Balance, beginning of year (shares) at Mar. 31, 2021			10	646
Balance, beginning of year at Mar. 31, 2021	19,843	19,171	$ 0	$ 1	32,866	(22,958)	11,144	(1,882)	672
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation activity	35	35			35
Preferred stock dividends	(14)	(14)					(14)
Common stock dividends	(158)	(158)					(158)
Noncontrolling interests	(129)	(1)					(1)		(128)
Net earnings	1,049	1,036					1,036		13
Other comprehensive income (loss)	30	29						29	1
Balance, end of year (shares) at Jun. 30, 2021			10	646
Balance, end of year at Jun. 30, 2021	$ 20,656	$ 20,098	$ 0	$ 1	$ 32,901	$ (22,958)	$ 12,007	$ (1,853)	$ 558

[1] Primarily reflects the acquisition of Miramax.