Note 7 - Share Repurchase Program (Details Textual) $ in Thousands		3 Months Ended				12 Months Ended
	Aug. 13, 2020	Dec. 31, 2022 shares	Sep. 30, 2022 shares	Jun. 30, 2022 USD ($) shares	Mar. 31, 2022 USD ($) shares	Dec. 31, 2023 USD ($) shares	Dec. 31, 2022 USD ($)	May 03, 2022 USD ($) shares	Aug. 31, 2020 shares	Aug. 31, 2019 USD ($) shares
Stock Repurchase Program, Authorized Amount | $								$ 50,000		$ 34,000
Stock Repurchase Program, Number of Shares Authorized to be Repurchased | shares								3,100,000	2,700,000	1,800,000
Stock Repurchased and Retired During Period, Shares | shares		0	0	963,000	1,300,000	0
Stock Repurchased and Retired During Period, Value | $				$ 16,800	$ 25,000		$ 41,753
Stock Repurchase Program, Remaining Authorized Repurchase Amount | $						$ 33,200
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased | shares						2,200,000
Stock Split To [Member]
Stockholders' Equity Note, Stock Split, Conversion Ratio	3
Stock Split from [Member]
Stockholders' Equity Note, Stock Split, Conversion Ratio	2