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Investments (Equity Method Investments) (Details) - USD ($) |  | 1 Months Ended | 3 Months Ended | 12 Months Ended |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | ---
Jan. 01, 2016 | Aug. 31, 2019 | May 31, 2019 | Apr. 30, 2018 | Jul. 31, 2017 | Mar. 31, 2019 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017 | Apr. 30, 2019 | Feb. 28, 2018 | Aug. 31, 2016 | Jul. 31, 2016
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Equity in net income (losses) of investees, net |  |  |  |  |  |  | $ (505,000,000) | $ (364,000,000) | $ 107,000,000 |  |  |  |
Equity method investments |  |  |  |  |  |  | 5,347,000,000 | 4,035,000,000 |  |  |  |  |
Proceeds from collateralized obligation |  | $ 5,200,000,000 |  |  |  |  | 5,175,000,000 | 0 | 0 |  |  |  |
Collateralized obligation |  |  |  |  |  |  | 5,166,000,000 | 0 |  |  |  |  |
Investment securing collateralized obligation |  |  |  |  |  |  | 694,000,000 | 0 |  |  |  |  |
NBCUniversal Media LLC [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Equity in net income (losses) of investees, net |  |  |  |  |  |  | (402,000,000) | (371,000,000) | (201,000,000) |  |  |  |
Equity method investments |  |  |  |  |  |  | 1,156,000,000 | 707,000,000 |  |  |  |  |
Proceeds from collateralized obligation |  | $ 5,200,000,000 |  |  |  |  | 5,175,000,000 | 0 | 0 |  |  |  |
Collateralized obligation |  |  |  |  |  |  | 5,166,000,000 | 0 |  |  |  |  |
Investment securing collateralized obligation |  |  |  |  |  |  | 694,000,000 | 0 |  |  |  |  |
Atairos [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Pretax gain, sale of business to Atairos |  |  |  | $ 200,000,000 | $ 105,000,000 |  |  |  |  |  |  |  |
Atairos [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Term of agreement | 12 years |  |  |  |  |  |  |  |  |  |  |  |
Funding commitment |  |  |  |  |  |  |  |  |  |  | $ 5,000,000,000 |  |
Management fee funding commitment |  |  |  |  |  |  |  |  |  |  | 45,000,000 |  |
Percent of losses | 99.00% |  |  |  |  |  |  |  |  |  |  |  |
Percentage of residual returns | 86.00% |  |  |  |  |  |  |  |  |  |  |  |
Equity in net income (losses) of investees, net |  |  |  |  |  |  | (64,000,000) | (31,000,000) | 281,000,000 |  |  |  |
Cash capital contributions for equity method investments |  |  |  |  |  |  | 571,000,000 | 282,000,000 | 994,000,000 |  |  |  |
Equity method investments |  |  |  |  |  |  | 3,200,000,000 | 2,700,000,000 |  |  |  |  |
Atairos [Member] | Minimum [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Funding commitment by management company investors |  |  |  |  |  |  |  |  |  |  | 50,000,000 |  |
Atairos [Member] | Maximum [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Funding commitment by management company investors |  |  |  |  |  |  |  |  |  |  | $ 100,000,000 |  |
Atairos [Member] | Variable Interest Entity, Not Primary Beneficiary [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Unfunded capital commitment |  |  |  |  |  |  | 2,200,000,000 |  |  |  |  |  |
Atairos [Member] | Former CFO [Member] | Minimum [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Funding commitment by management company investors | $ 40,000,000 |  |  |  |  |  |  |  |  |  |  |  |
Hulu [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Equity in net income (losses) of investees, net |  |  |  |  |  |  | (473,000,000) | (454,000,000) | (276,000,000) |  |  |  |
Equity method investments |  |  |  |  |  |  |  | 248,000,000 |  |  |  |  |
Ownership percentage |  |  | 33.00% |  |  |  |  |  |  | 30.00% |  | 30.00% | 33.00%
Cash capital contributions for equity method investments |  |  | $ 477,000,000 |  |  |  | 903,000,000 | 454,000,000 | 300,000,000 |  |  |  |
Maximum total capital call in annual period |  |  | $ 1,500,000,000 |  |  |  |  |  |  |  |  |  |
Ownership percentage floor |  |  | 21.00% |  |  |  |  |  |  |  |  |  |
Fair market value assessment floor for put and call option |  |  | $ 27,500,000,000 |  |  |  |  |  |  |  |  |  |
Ownership percentage representing fair market value floor for put and call option |  |  | 100.00% |  |  |  |  |  |  |  |  |  |
Minimum guaranteed proceeds floor for put and call option |  |  | $ 5,800,000,000 |  |  |  |  |  |  |  |  |  |
Deferred gain |  |  |  |  |  | $ 159,000,000 |  |  |  |  |  |  |
Hulu [Member] | NBCUniversal Media LLC [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Equity in net income (losses) of investees, net |  |  |  |  |  |  | (473,000,000) | (454,000,000) | (276,000,000) |  |  |  |
Equity method investments |  |  |  |  |  |  |  | 248,000,000 |  |  |  |  |
Ownership percentage |  |  | 33.00% |  |  |  |  |  |  | 30.00% |  | 30.00% | 33.00%
Cash capital contributions for equity method investments |  |  | $ 477,000,000 |  |  |  | 903,000,000 | $ 454,000,000 | $ 300,000,000 |  |  |  |
Maximum total capital call in annual period |  |  | $ 1,500,000,000 |  |  |  |  |  |  |  |  |  |
Ownership percentage floor |  |  | 21.00% |  |  |  |  |  |  |  |  |  |
Fair market value assessment floor for put and call option |  |  | $ 27,500,000,000 |  |  |  |  |  |  |  |  |  |
Ownership percentage representing fair market value floor for put and call option |  |  | 100.00% |  |  |  |  |  |  |  |  |  |
Minimum guaranteed proceeds floor for put and call option |  |  | $ 5,800,000,000 |  |  |  |  |  |  |  |  |  |
Deferred gain |  |  |  |  |  | $ 159,000,000 |  |  |  |  |  |  |
Hulu [Member] | AT&T Inc. [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Ownership percentage |  |  | 10.00% |  |  |  |  |  |  |  |  |  |
Hulu [Member] | AT&T Inc. [Member] | NBCUniversal Media LLC [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Ownership percentage |  |  | 10.00% |  |  |  |  |  |  |  |  |  |
Hulu [Member] | Time Warner, Inc. [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Ownership percentage |  |  |  |  |  |  |  |  |  |  |  | 10.00% |
Hulu [Member] | Time Warner, Inc. [Member] | NBCUniversal Media LLC [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Ownership percentage |  |  |  |  |  |  |  |  |  |  |  | 10.00% |
Level 2 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Estimated fair value of collateralized obligation |  |  |  |  |  |  | 5,200,000,000 |  |  |  |  |  |
Level 2 [Member] | NBCUniversal Media LLC [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Estimated fair value of collateralized obligation |  |  |  |  |  |  | $ 5,200,000,000 |  |  |  |  |  |

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