Note 3 - Share-based Compensation - Components of Share-based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2022	Mar. 31, 2021
Restricted Stock Units (RSUs) [Member]
Pretax compensation expense	$ 12,975	$ 10,778
Tax benefit	3,250	2,727
Share unit expense, net of tax	9,725	8,051
Performance Shares [Member]
Pretax compensation expense	6,166	4,189
Tax benefit	1,545	1,060
Share unit expense, net of tax	$ 4,621	$ 3,129

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

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