Note 7 - Stockholders' Equity and Stock Incentive Plans - Share Repurchases (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended					6 Months Ended
		Jun. 30, 2022		Mar. 31, 2022	Jun. 30, 2021		Jun. 30, 2022		Jun. 30, 2021
Shares repurchased (2) (in shares)	[1],[2]	3,018			0		5,115		0
Total cost, including brokerage fees		$ 167,984	[2]	$ 131,789	$ 0	[2]	$ 299,773	[2]	$ 0	[2]
Average repurchase price per share (3) (in dollars per share)	[2],[3]	$ 55.66			$ 0		$ 58.61		$ 0

[1] All shares repurchased have been retired and constitute authorized but unissued shares.

[2] Shares repurchased reflect repurchases settled during the three and six months ended June 30, 2022. These amounts exclude repurchases, if any, traded but not yet settled on or before June 30, 2022.

[3] Amounts in the table may not recalculate exactly due to rounding. Average repurchase price per share is calculated based on unrounded numbers.