Business organization (Details) member in Millions	6 Months Ended
Business organization (Details) member in Millions	Jun. 30, 2025 segment store member state	Mar. 31, 2025 store	Dec. 31, 2024 store	Jun. 30, 2024 store	Mar. 31, 2024 store	Dec. 31, 2023 store	Aug. 05, 2015
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Number of members \| member	20.8
Number of owned and franchised locations \| store	2,762	2,741	2,722	2,617	2,599	2,575
Number of states in which entity operates \| state	50
Number of reportable segments \| segment	3
Pla-Fit Holdings, LLC
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Percentage of voting power (in percentage)	100.00%						100.00%
Percentage of ownership (in percentage)	99.60%
Economic interest	0.40%
Planet Intermediate, LLC \| Pla-Fit Holdings, LLC
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Percentage of ownership (in percentage)							100.00%
Planet Fitness Holdings, LLC \| Planet Intermediate, LLC
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Percentage of ownership (in percentage)							100.00%

Planet Fitness, Inc. 10-Q