Statement Of Changes In Net Assets Available For Benefits [Abstract]
| Concept |
2021-01-01 to 2021-12-31 |
2020-01-01 to 2020-12-31 |
2019-01-01 to 2019-12-31 |
|---|---|---|---|
| Statement of changes in net assets available for benefits [abstract] | |||
| Reconciliation of changes in net assets available for benefits [abstract] | |||
| Changes in net assets available for benefits [abstract] | |||
| Administrative expenses |
300,000,000
USD
|
267,000,000
USD
|
385,000,000
USD
|
| Tax expense (income) |
96,000,000
USD
|
20,000,000
USD
|
156,000,000
USD
|