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Supplemental Financial Information (Summary of Future Minimum Rental Commitments for Operating Leases Under New Accounting Guidance) (Details) $ in Millions | Mar. 31, 2019 USD ($)
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Lessee, Lease, Description [Line Items] |
Remaining nine months of 2019 | $ 669
2020 | 832
2021 | 724
2022 | 592
2023 | 501
Thereafter | 2,536
Total future minimum lease payments | 5,854
Less: imputed interest | 1,147
Total liability | 4,707
NBCUniversal Media LLC [Member] |
Lessee, Lease, Description [Line Items] |
Remaining nine months of 2019 | 175
2020 | 243
2021 | 210
2022 | 176
2023 | 152
Thereafter | 1,397
Total future minimum lease payments | 2,353
Less: imputed interest | 651
Total liability | $ 1,702

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