Nature of the Business - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands			3 Months Ended	6 Months Ended
	Jun. 25, 2021	Jun. 14, 2021	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Organisation incorporated date				Jan. 28, 2021
Proceeds from initial public offering, net of underwriters discounts and commissions and deferred offering costs				$ 0	$ 554,169
Life Stance Health Foundation [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Issuance of common , Shares				500,000
Cash payment for restructuring				$ 1,000
Aggregate cost				$ 10,000
LifeStance TopCo
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Number of units converted				1,046,196,000
LifeStance [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Proceeds from initial public offering, net of underwriters discounts and commissions and deferred offering costs		$ 548,905
Payments for underwriting expense		32,472
Deferred offering costs		$ 9,023
Conversion of common units into common stock upon closing of initial public offering, Shares				310,083,000
Common Stock Subject To Service-Based Vesting [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Conversion of common units into common stock upon closing of initial public offering, Shares				30,766,000
Common Stock [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Conversion of common units into common stock upon closing of initial public offering, Shares			295,663		295,663
Class B Profits Interests Units [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Number of units converted				152,620
Selling Shareholders [Member] | Common Stock [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Issuance of common , Shares		7,200,000
Shares offering, price per share		$ 18.00
IPO [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Shares offering, price per share				$ 18.00
IPO [Member] | LifeStance [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Issuance of common , Shares		32,800,000
IPO [Member] | Common Stock [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Issuance of common , Shares			32,800		32,800
Over-Allotment Option
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Issuance of common , Shares	6,000,000