Earnings Per Share (Calculated Earnings (Loss) Per Share) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Numerator:
Net income	$ 300	$ 987	$ 707	$ 1,405
Less:
Net income attributable to noncontrolling interests	(25)	(36)	(53)	(65)
Net income attributable to redeemable noncontrolling interests	(4)	(4)	(6)	(9)
Redeemable noncontrolling interest adjustments to redemption value	1	1	1	(4)
Net income allocated to Discovery, Inc. Series A, B and C common and Series C-1 convertible preferred stockholders for basic net income per share	243	854	581	1,195
Allocation of net income to:
Total	243	854	581	1,195
Series A-1 Convertible Preferred Stock
Less:
Allocation of undistributed income to Series A-1 convertible preferred stock	(29)	(94)	(68)	(132)
Add:
Allocation of undistributed income to Series A-1 convertible preferred stockholders	29	94	68	132
Series A, B and C Common Stock and C1 Preferred Stock
Less:
Net income allocated to Discovery, Inc. Series A, B and C common and Series C-1 convertible preferred stockholders for basic net income per share	243	854	581	1,195
Allocation of net income to:
Total	243	854	581	1,195
Series A, B and C Common Stock
Less:
Net income allocated to Discovery, Inc. Series A, B and C common and Series C-1 convertible preferred stockholders for basic net income per share	205	702	491	980
Allocation of net income to:
Total	205	702	491	980
Add:
Net income allocated to Discovery, Inc. Series A, B and C common stockholders for diluted net income per share	$ 272	$ 948	$ 649	$ 1,327
Denominator — weighted average:
Series A, B and C common shares outstanding — basic (in shares)	508	528	513	526
Impact of assumed preferred stock conversion (in shares)	165	185	165	186
Dilutive effect of share-based awards (in shares)	1	3	2	3
Series A, B and C common shares outstanding — diluted (in shares)	674	716	680	715
Basic net income per share allocated to:
Basic net income (loss) per share (in dollars per share)	$ 0.40	$ 1.33	$ 0.96	$ 1.86
Diluted net income per share allocated to:
Diluted net income (loss) per share (in dollars per share)	$ 0.40	$ 1.33	$ 0.95	$ 1.86
Series C-1 Convertible Preferred Stock
Less:
Net income allocated to Discovery, Inc. Series A, B and C common and Series C-1 convertible preferred stockholders for basic net income per share	$ 38	$ 152	$ 90	$ 215
Allocation of net income to:
Total	$ 38	$ 152	$ 90	$ 215
Denominator — weighted average:
Series C-1 convertible preferred stock outstanding — basic and diluted (in shares)	5	6	5	6
Basic net income per share allocated to:
Basic net income (loss) per share (in dollars per share)	$ 7.83	$ 25.76	$ 18.55	$ 36.08
Diluted net income per share allocated to:
Diluted net income (loss) per share (in dollars per share)	$ 7.81	$ 25.67	$ 18.49	$ 35.95