Note 9 - Dividends and Dividend Equivalents (Tables)

12 Months Ended

Dec. 31, 2020

Notes Tables

Dividends Declared [Table Text Block]

	Year Ended December 31,
	2020		2019		2018
Dividend declared per share	$	2.00	$	1.60	$	1.20
Total amount	$	89,832	$	69,196	$	50,803