Fair Value Measurements - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions |
12 Months Ended | |||
|---|---|---|---|---|
Dec. 31, 2021 |
Jun. 30, 2021 |
Jun. 22, 2021 |
Dec. 31, 2020 |
|
| Class of Warrant or Right, Outstanding | 33,480,000 | |||
| Private Placement Warrant [Member] | ||||
| Expected volatility | 67.80% | |||
| Class of Warrant or Right, Outstanding | 10,280,000 | |||
| Gains on Revaluation of Warrants | $ 36.0 | |||
| Old Talkspace | Common Stock | ||||
| Class of Warrant or Right, Outstanding | 60,000 | |||
| Class of Warrant or Right, Exercise Price of Warrants or Rights | $ 0.44 | |||
| Old Talkspace | Preferred D stock | ||||
| Class of Warrant or Right, Outstanding | 50,881 | |||
| Class of Warrant or Right, Exercise Price of Warrants or Rights | $ 2.75 |