Description of the business and recent developments: Financial instruments (Details) $ in Millions	Sep. 30, 2022 USD ($)
Level 2 \| Interest Rate Swap
Financial instruments
long-term liability	$ 54.7
Senior secured 2026 Notes
Financial instruments
Senior notes	500.0
Senior secured 2026 Notes \| Level 2
Financial instruments
Senior notes, fair value	438.8
Senior unsecured 2027 Notes
Financial instruments
Senior notes	450.0
Senior unsecured 2027 Notes \| Level 2
Financial instruments
Senior notes, fair value	$ 426.4

Amount of obligation due after one year or beyond the normal operating cycle, if longer.

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+ Details