Note 8 - Stock-based Compensation - RSU Stock-based Payment Awards (Details) - Restricted Stock Units (RSUs) [Member]	3 Months Ended
	Mar. 31, 2023 $ / shares shares
Balance at January 1, 2023 (in shares) | shares	3,652
Balance at January 1, 2023 (in dollars per share) | $ / shares	$ 36.49
Vested (1) (in shares) | shares	(742)	[1]
Vested (1) (in dollars per share) | $ / shares	$ 33.72	[1]
Outstanding at March 31, 2023 (in shares) | shares	2,910
Outstanding at March 31, 2023 (in dollars per share) | $ / shares	$ 38.28

[1] The RSUs vested during the three months ended March 31, 2023 were settled on a hybrid basis. The Company withheld 274 shares of common stock and, in lieu of delivering such shares, paid the RSU holder an amount in cash equal to the fair market value of such shares on the vesting date, representing the holder's approximate tax liability associated with the vesting.