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Note 13 - Retirement Benefit Plans - Accumulated Benefit Obligations (Details) - USD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019
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UNITED STATES | Nonqualified Plan [Member] |  |
Accumulated benefit obligation | $ 1.2 | $ 1.3
Foreign Plan [Member] | Pension Plan [Member] | UK Pension Plan [Member] |  |
Accumulated benefit obligation | 12.2 | 10.4
Foreign Plan [Member] | Pension Plan [Member] | German Pension Plan [Member] |  |
Accumulated benefit obligation | 1.2 | 1.0
Foreign Plan [Member] | Pension Plan [Member] | Italian Pension Plan [Member] |  |
Accumulated benefit obligation | $ 4.2 | $ 4.3

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- Definition Amount of actuarial present value of benefits attributed to employee service rendered, excluding assumptions about future compensation level. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 + Details
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