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Income Taxes - Reconciliation of statutory to effective income tax rate (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Federal Statutory Rate	21.00%	21.00%	21.00%
Permanent differences	(0.30%)	(1.20%)	(13.10%)
State taxes, net of Federal benefit	0.00%	0.00%	(0.10%)
Rate change	2.50%	(0.20%)	(3.50%)
Foreign earnings taxed at different rates than U.S.	(3.90%)	(0.30%)	(3.30%)
Valuation allowance	(15.90%)	(4.30%)	72.80%
Helguvik investment	26.40%	0.00%	0.00%
Foreign restructuring	0.00%	(2.30%)	0.00%
Foreign dividends and inclusions	(10.10%)	(1.50%)	0.00%
Net operating loss expiration and remeasurement	(5.20%)	(10.80%)	(66.20%)
Changes in uncertain tax reserves	1.30%	1.40%	1.20%
Other	(0.30%)	0.60%	1.00%
Effective tax rate	15.50%	2.40%	9.80%

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- Definition

Effective Income Tax Rate Reconciliation, Foreign Dividends and Inclusions, Percentage

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Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to changes in the valuation allowance for deferred tax assets.

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to income tax contingencies. Includes, but not limited to, domestic tax contingency, foreign tax contingency, state and local tax contingency, and other contingencies.

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