Fair Value Measurements - Summary of warrants (Detail)
$ in Thousands
12 Months Ended
Dec. 31, 2021
USD ($)
Private Placement Warrants  
Class Of Warrant Or Right [Line Items]  
Fair value as of beginning $ 0
Acquired in Business Combination 32,399
Issued in connection with closing of the Forward Purchase Agreement 7,879
Change in value (36,208)
Converted into equity
Fair value as of ending 4,070
Old Talkspace Warrants  
Class Of Warrant Or Right [Line Items]  
Fair value as of beginning 444
Acquired in Business Combination
Issued in connection with closing of the Forward Purchase Agreement
Change in value 165
Converted into equity (609)
Fair value as of ending