Note 3 - Share-based Compensation - Components of Share-based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Restricted Stock Units (RSUs) [Member]
Pretax compensation expense	$ 14,655	$ 11,677	$ 42,550	$ 34,669
Tax benefit	3,664	2,931	10,638	8,702
Restricted share unit expense, net of tax	10,991	8,746	31,912	25,967
Performance Shares [Member]
Pretax compensation expense	5,498	4,269	17,187	12,742
Tax benefit	1,375	1,071	4,297	3,198
Restricted share unit expense, net of tax	$ 4,123	$ 3,198	$ 12,890	$ 9,544

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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