Employee Compensation and Benefit Plans - Stock Awards (Details) - Long-Term Stock Incentive Program - Common Stock Outstanding |
Apr. 22, 2020
shares
|
|---|---|
| T-Mobile | |
| Employee Stock Ownership Plan (ESOP) Disclosures [Line Items] | |
| Shares of T-Mobile common stock issuable upon exercise or settlement | 7,043,843 |
| Shares of common stock available for issuance | 12,420,945 |
| Additional shares of T-Mobile common stock subject to awards granted | 5,839,436 |
| Sprint | |
| Employee Stock Ownership Plan (ESOP) Disclosures [Line Items] | |
| Number of shares registered | 25,304,224 |