Note 15 - Share-based Compensation - Restricted Stock Unit/Awards Activity (Details) - Restricted Stock Units (RSUs) [Member] - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	9 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Outstanding, number of shares (in shares)	770
Outstanding, weighted average fair value (in dollars per share)	$ 25.18
Outstanding, aggregate intrinsic value	$ 16,333	$ 9,143
Granted, number of shares (in shares)	1,185
Granted, weighted average fair value (in dollars per share)	$ 11.42
Granted, aggregate intrinsic value	$ 13,536
Released, number of shares (in shares)	(465)
Released, weighted average share price on date of release (in dollars per share)	$ 11.77
Released, weighted average fair value (in dollars per share)	$ 21.17
Released, aggregate intrinsic value	$ 5,472
Cancelled/Forfeited, number of shares (in shares)	(38)
Cancelled/Forfeited, weighted average fair value (in dollars per share)	$ 15.14
Cancelled/Forfeited, aggregate intrinsic value	$ 426
Outstanding, number of shares (in shares)	1,452
Outstanding, weighted average fair value (in dollars per share)	$ 15.5
Vested and expected to vest, number of shares (in shares)	1,452
Vested and expected to vest, weighted average fair value (in dollars per share)	$ 15.5
Vested and expected to vest, aggregate intrinsic value	$ 16,333