Income taxes - Income tax expense reconciliation (Detail) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
|
| Income tax expense reconciliation | |||
| Earnings before income taxes | $ 4,001 | $ 23,838 | $ 33,667 |
| Hypothetical income tax expense computed at the U.S. federal statutory rate | 840 | 8,343 | 11,783 |
| Dividends received deduction and tax exempt interest | (393) | (905) | (789) |
| State income taxes, less U.S. federal income tax benefit | 138 | 465 | 361 |
| Foreign tax rate differences | 271 | (339) | (421) |
| U.S. income tax credits | (711) | (636) | (518) |
| Non-taxable exchange of investments | (1,143) | ||
| Net benefit from the enactment of the TCJA | (302) | (28,200) | |
| Other differences, net | (164) | (243) | (33) |
| Total income taxes | $ (321) | $ (21,515) | $ 9,240 |