Interim financial statements (Details) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Investments In Debt And Equity Securities
Debt Instrument [Line Items]
Investments restricted for statutory reserve funds	$ 494.4	$ 492.0
Cash and Cash Equivalents
Debt Instrument [Line Items]
Investments restricted for statutory reserve funds	$ 3.8	$ 4.4

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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+ Details