Fair Value Measurements - Additional Information (Detail) - USD ($) $ in Millions |
Dec. 31, 2018 |
Dec. 31, 2017 |
---|---|---|
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Other identifiable intangibles, net | $ 5,951 | $ 6,591 |
Level 1 and Level 2 [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Fair value of total debt | 10,850 | $ 10,432 |
Level 3 [Member] | Non-recurring Fair Value Measurements [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Fair value of assets | 17,878 | |
Cost and equity method investments | 127 | |
Goodwill | 11,800 | |
Other identifiable intangibles, net | $ 5,951 |