Quarterly Information (Unaudited) (Parenthetical) (Detail) - USD ($) $ / shares in Units, $ in Millions |
3 Months Ended | 12 Months Ended | |||||
|---|---|---|---|---|---|---|---|
Jun. 30, 2019 |
Dec. 31, 2018 |
Jun. 30, 2018 |
Dec. 31, 2017 |
Jun. 30, 2019 |
Jun. 30, 2018 |
Jun. 30, 2017 |
|
| Quarterly Financial Information [Line Items] | |||||||
| Provision (benefit) for income taxes | $ 4,448 | $ 19,903 | $ 4,412 | ||||
| Transfer of Intangible Properties | |||||||
| Quarterly Financial Information [Line Items] | |||||||
| Provision (benefit) for income taxes | $ (2,600) | (2,600) | |||||
| Increase (decrease) in net income | $ 2,400 | ||||||
| Decrease (increase) in diluted earnings per share | $ (0.34) | $ 0.02 | $ (0.31) | ||||
| Tax Cuts and Jobs Act | |||||||
| Quarterly Financial Information [Line Items] | |||||||
| Provision (benefit) for income taxes | $ 157 | $ (104) | $ 13,800 | $ 157 | $ 13,700 | ||
| Decrease (increase) in diluted earnings per share | $ (0.01) | $ 1.78 | $ 1.75 | ||||