Income Taxes - Components of Income before Taxes, Less Net Income (Loss) Attributable to Noncontrolling Interests (Detail) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
|
| Components Of Income Before Tax Less Noncontrolling Interest [Line Items] | |||
| Income tax expense based on components of income before taxes, net income (loss) attributable to non-controlling interests | $ 4,595 | $ 4,425 | $ 3,954 |
| Domestic [Member] | |||
| Components Of Income Before Tax Less Noncontrolling Interest [Line Items] | |||
| Income tax expense based on components of income before taxes, net income (loss) attributable to non-controlling interests | 2,840 | 2,946 | 2,814 |
| Foreign [Member] | |||
| Components Of Income Before Tax Less Noncontrolling Interest [Line Items] | |||
| Income tax expense based on components of income before taxes, net income (loss) attributable to non-controlling interests | $ 1,755 | $ 1,479 | $ 1,140 |