Summary of significant accounting policies - Narrative (Details) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2025 USD ($) segment	Jun. 30, 2024 USD ($) segment	Jun. 30, 2025 USD ($) segment	Jun. 30, 2024 USD ($)
Property, Plant and Equipment [Line Items]
Number of operating segments \| segment	2	2	2
Number of reportable segments \| segment	2	2	2
Revenue recognized	$ 158.4	$ 152.6	$ 225.7	$ 213.6
Amortization period	4 years		4 years
Renewal term	18 months		18 months
Breakage
Property, Plant and Equipment [Line Items]
Revenue recognized	$ 2.6	$ 0.0	$ 2.6	$ 0.0
Previously satisfied performance obligations			$ 2.5
Internal use software
Property, Plant and Equipment [Line Items]
Estimated useful lives	3 years		3 years
Content assets
Property, Plant and Equipment [Line Items]
Estimated useful lives	2 years		2 years

Capitalized Contract Cost, Amortization Period, Renewal Term

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Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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