Income Taxes - Components of Income Tax Benefit (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Current income tax provision, Federal	$ 230	$ 463	$ 0
Current income tax provision, State	452	325	1,589
Current income tax provision	682	788	1,589
Deferred income tax provision, Federal	3,549	836	(17,134)
Deferred income tax provision, State	(1,531)	(1,794)	(4,776)
Deferred income tax provision	2,018	(958)	(21,910)
Total income tax provision (benefit)	$ 2,700	$ (170)	$ (20,321)

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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LifeStance Health Group, Inc. 10-K