Significant Transactions (Universal Studios Japan) (Details) - USD ($) $ in Millions |
12 Months Ended | |||
|---|---|---|---|---|
Apr. 06, 2017 |
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
|
| Business Acquisition [Line Items] | ||||
| Payments to acquire additional interest in noncontrolling interest | $ 0 | $ 2,299 | $ 0 | |
| NBCUniversal Media LLC [Member] | ||||
| Business Acquisition [Line Items] | ||||
| Payments to acquire additional interest in noncontrolling interest | $ 0 | $ 2,299 | $ 0 | |
| Universal Studios Japan [Member] | ||||
| Business Acquisition [Line Items] | ||||
| Payments to acquire additional interest in noncontrolling interest | $ 2,300 | |||
| Universal Studios Japan [Member] | NBCUniversal Media LLC [Member] | ||||
| Business Acquisition [Line Items] | ||||
| Payments to acquire additional interest in noncontrolling interest | $ 2,300 | |||