Income Taxes (Summary of Valuation Allowance) (Details) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
|
| Deferred Tax Assets, Valuation Allowance [Roll Forward] | |||
| Balance at beginning of year | $ 2,324 | $ 71 | $ 0 |
| Additions to valuation allowance related to Altria’s initial Investment in Cronos | 0 | 352 | 0 |
| Additions to valuation allowance charged to income tax expense | 692 | 2,063 | 71 |
| Reductions to valuation allowance credited to income tax benefit | (200) | (159) | 0 |
| Foreign currency translation | 1 | (3) | 0 |
| Balance at end of year | $ 2,817 | $ 2,324 | $ 71 |