Summary of significant accounting policies - Narrative (Details) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2025 USD ($) segment	Sep. 30, 2024 USD ($) segment	Sep. 30, 2025 USD ($) segment	Sep. 30, 2024 USD ($) segment
Property, Plant and Equipment [Line Items]
Number of operating segments \| segment	2	2	2	2
Number of reportable segments \| segment	2	2	2	2
Revenue recognized	$ 153.4	$ 152.8	$ 266.9	$ 252.9
Amortization period (in years)	4 years		4 years
Renewal term	18 months		18 months
Breakage
Property, Plant and Equipment [Line Items]
Revenue recognized	$ 0.0	$ 0.0	$ 2.6	$ 0.0
Previously satisfied performance obligations			$ 2.5
Internal use software
Property, Plant and Equipment [Line Items]
Estimated useful lives (in years)	3 years		3 years
Content assets
Property, Plant and Equipment [Line Items]
Estimated useful lives (in years)	2 years		2 years

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Amortization period of cost capitalized in obtaining or fulfilling contract with customer, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

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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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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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