Note 8 - Dividends and Dividend Equivalents - Cash Dividends (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
Dec. 31, 2022	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Dividend declared per share (in dollars per share)	$ 0.75	$ 3.00	$ 2.40	$ 2.00
Total amount		$ 140,337	$ 110,206	$ 89,832

Amount of paid and unpaid common stock dividends declared with the form of settlement in cash, stock and payment-in-kind (PIK).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI https://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 405
-Section 45
-Paragraph 2
-URI https://asc.fasb.org/extlink&oid=6957935&loc=d3e64057-112817

Name:	us-gaap_DividendsCommonStock
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration