Fair Value Measurements - Additional Information (Detail) - $ / shares	6 Months Ended
	Jun. 30, 2021	Jun. 22, 2021	Dec. 31, 2020
Warrants outstanding		33,480,000
Private Placement Warrant [Member]
Percentage Volatilities Of Private Placement Warrant Estimated Before The Expected Business Combination	50.00%
Warrants outstanding		10,280,000
Old Talkspace | Preferred D stock
Warrants outstanding			50,881
Warrants, exercise price			$ 2.75
Old Talkspace | Common stock
Warrants outstanding			60,000
Warrants, exercise price			$ 0.44