Benefit Plans - 401(k) Savings Plan (Narrative) (Details) - Sirius XM Savings Plan - USD ($) $ in Millions |
3 Months Ended | |
|---|---|---|
Mar. 31, 2025 |
Mar. 31, 2024 |
|
| Defined Benefit Plan Disclosure [Line Items] | ||
| Minimum of employee contributions of pre-tax eligible earnings to company 401(k) savings plan | 1.00% | |
| Maximum of employee contributions of pre-tax eligible earnings to company 401(k) savings plan | 50.00% | |
| Percent of Company match of employee's voluntary contributions | 50.00% | |
| Percent of employee's pre-tax salary | 6.00% | |
| Maximum annual contributions per employee, percent | 3.00% | |
| Vesting percentage of employer contributions for each year of employment | 33.33% | |
| Savings plan, fully vested period | 3 years | |
| Recognized cost | $ 5 | $ 6 |