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Supplemental Financial Information (Leases Narrative) (Details) $ in Millions | 3 Months Ended
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Mar. 31, 2019 USD ($)
Lessee, Lease, Description [Line Items] |
Operating Lease Expense Inclusive Of Short Term And Variable Lease Expenses | $ 274
Weighted average remaining lease term for operating leases | 10 years
Weighted average discount rate used to calculate operating lease liabilities | 3.84%
Cash payments for operating leases | $ 213
NBCUniversal Media LLC [Member] |
Lessee, Lease, Description [Line Items] |
Operating Lease Expense Inclusive Of Short Term And Variable Lease Expenses | $ 111
Weighted average remaining lease term for operating leases | 15 years
Weighted average discount rate used to calculate operating lease liabilities | 4.03%
Cash payments for operating leases | $ 64

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