Note 9 - Product Warranty Obligations - Reconciliation of Product Warranty Liability (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Balance at beginning of period	$ 101,491	$ 65,297	$ 94,213	$ 59,218
Payments	(18,434)	(9,282)	(31,458)	(19,061)
Provision for warranty issued	21,668	17,164	43,093	31,994
Changes in estimates for pre-existing warranties	5,613	1,579	4,490	2,607
Balance at end of period	110,338	74,758	110,338	74,758
Balance at beginning of period	115,923	93,182	111,647	89,788
Deferred revenue contracts issued	11,332	12,168	20,878	20,199
Amortization of deferred revenue contracts	(5,357)	(4,866)	(10,627)	(9,503)
Balance at end of period	$ 121,898	$ 100,484	$ 121,898	$ 100,484