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Summary of Tax Returns Periods Subject to Examination by Federal, State and Foreign Tax Authorities (Detail) | 12 Months Ended
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Dec. 31, 2020
United States | Earliest Tax Year |
Income Tax Examination [Line Items] |
Fiscal year subject to examination | 2017
United States | Latest Tax Year |
Income Tax Examination [Line Items] |
Fiscal year subject to examination | 2020
Sweden | Earliest Tax Year |
Income Tax Examination [Line Items] |
Fiscal year subject to examination | 2013
Sweden | Latest Tax Year |
Income Tax Examination [Line Items] |
Fiscal year subject to examination | 2020

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- Definition Tax year that remains open to examination under enacted tax laws, in CCYY format. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32718-109319 + Details
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