Note 14 - Earnings Per Share - Reconciliation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Net income attributable to Generac Holdings Inc.		$ 44,861	$ 33,645
Redeemable noncontrolling interest redemption value adjustment		2,432	(7,665)
Net income attributable to common shareholders		$ 47,293	$ 25,980
Weighted average shares, basic (in shares)		61,762,260	61,943,495
Dilutive effect of stock compensation awards (in shares)	[1]	461,378	531,441
Diluted shares (in shares)		62,223,638	62,474,936
Basic (in dollars per share)		$ 0.77	$ 0.42
Diluted (in dollars per share)		$ 0.76	$ 0.42

[1] Excludes approximately 71,800 and 93,600 stock options for the three months ended March 31, 2019 and 2018, respectively, as the impact of such awards was anti-dilutive.