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Face (par) amount of debt instrument at time of issuance.

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Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

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Gross amount of debt extinguished.

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Long-term debt: Debt extinguishment and redemptions of 2022 Notes (Details) € in Millions			1 Months Ended		12 Months Ended
	Dec. 01, 2021 USD ($)	Apr. 06, 2021 USD ($)	Mar. 31, 2021 USD ($)	Jun. 30, 2020 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2021 EUR (€)	Dec. 31, 2020 USD ($)	Dec. 31, 2020 EUR (€)	Jun. 30, 2020 EUR (€)	Dec. 31, 2019 EUR (€)	Jun. 30, 2019 EUR (€)	Aug. 31, 2018 USD ($)	Dec. 31, 2016 USD ($)	Feb. 28, 2015 USD ($)
Long-term debt
Interest					$ 5,046,000		$ 8,268,000
Senior secured notes due 2022
Long-term debt
Principal amount plus accrued and unpaid interest (as a percent)			103.20%
Face amount			$ 115,900,000		$ 284,100,000
Interest	$ 11,500,000		400,000
Loss on debt purchase	$ 10,800,000		$ 3,900,000
Notice issued for redemption of debt		$ 45,000,000.0
Amount of debt redeemed		45,000,000.0
Redemption value		$ 1,900,000
Redemption price per $1,000 aggregate principal amount		41.41533
Accrued interest value		$ 400,000
Accrued interest per $1,000 aggregate principal amount		9.70486
Senior notes outstanding		$ 284,100,000
Senior unsecured 2024 Notes
Long-term debt
Principal amount plus accrued and unpaid interest (as a percent)					100.00%
Face amount					$ 397,000,000.0	€ 350.0		€ 350.0	€ 215.0	€ 135.0	€ 135.0
Loss on debt purchase				$ 600,000
Senior notes outstanding					$ 397,000,000.0	€ 350.0
Senior unsecured 2024 Notes \| Prior to June 30, 2021
Long-term debt
Principal amount plus accrued and unpaid interest (as a percent)					104.375%
Senior unsecured 2024 Notes \| After June 30, 2021
Long-term debt
Principal amount plus accrued and unpaid interest (as a percent)					102.188%
Senior notes
Long-term debt
Face amount												$ 70,000,000.0	$ 125,000,000.0	$ 250,000,000.0
Senior notes \| Prior to December 1, 2021
Long-term debt
Principal amount plus accrued and unpaid interest (as a percent)					100.00%