Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
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-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
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-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
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Name:	us-gaap_DebtInstrumentCarryingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Description of the business and recent developments: Financial instruments (Details) - Jun. 30, 2021 € in Millions, $ in Millions	USD ($)	EUR (€)
Senior unsecured 2024 Notes
Financial instruments
Senior notes	$ 415.8	€ 350.0
Senior unsecured 2024 Notes \| Level 2
Financial instruments
Senior notes, fair value	424.1
Senior secured 2026 Notes
Financial instruments
Senior notes	500.0
Senior secured 2026 Notes \| Level 2
Financial instruments
Senior notes, fair value	$ 510.0