Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Excess Purchase Price over Predecessor Basis [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Parent [Member]	Noncontrolling Interest [Member]	Total [Member]	Total
Balance (in shares) at Dec. 31, 2013	68,767,367		(163,458)
Balance at Dec. 31, 2013	$ 688	$ 421,672	$ (6,571)	$ (202,116)	$ 105,813	$ (2,415)	$ 317,071		$ 317,071
Net unrealized gain (loss) on derivatives						(1,420)	(1,420)		(1,420)	$ (1,420)
Foreign currency translation adjustment						(3,082)	(3,082)		(3,082)	(3,082)
Common stock issued under equity incentive plans, net of shares withheld for employee taxes and strike price (in shares)	354,904
Common stock issued under equity incentive plans, net of shares withheld for employee taxes and strike price	$ 3	(10,378)					(10,375)		(10,375)
Net share settlement of restricted stock awards (in shares)			(34,854)
Net share settlement of restricted stock awards			$ (1,770)				(1,770)		(1,770)
Excess tax benefits from equity awards		10,972					10,972		10,972
Share-based compensation		12,612					12,612		12,612
Dividends declared		28					28		28
Pension liability adjustment						(8,850)	(8,850)		(8,850)	(8,850)
Net income attributable to Generac Holdings Inc.					174,613		174,613		174,613	174,613
Balance (in shares) at Dec. 31, 2014	69,122,271		(198,312)
Balance at Dec. 31, 2014	$ 691	434,906	$ (8,341)	(202,116)	280,426	(15,767)	489,799		489,799
Redemption value adjustment
Net unrealized gain (loss) on derivatives						(965)	(965)		(965)	(965)
Foreign currency translation adjustment						(7,624)	(7,624)		(7,624)	(7,624)
Common stock issued under equity incentive plans, net of shares withheld for employee taxes and strike price (in shares)	460,398
Common stock issued under equity incentive plans, net of shares withheld for employee taxes and strike price	$ 5	(9,626)					(9,621)		(9,621)
Net share settlement of restricted stock awards (in shares)			(65,763)
Net share settlement of restricted stock awards			$ (3,233)				(3,233)		(3,233)
Excess tax benefits from equity awards		9,559					9,559		9,559
Share-based compensation		8,241					8,241		8,241
Dividends declared		29					29		29
Pension liability adjustment						1,881	1,881		1,881	1,881
Net income attributable to Generac Holdings Inc.					77,747		77,747		77,747	77,747
Balance (in shares) at Dec. 31, 2015	69,582,669		(3,567,575)
Balance at Dec. 31, 2015	$ 696	443,109	$ (111,516)	(202,116)	358,173	(22,475)	465,871		465,871	465,871
Stock repurchases (in shares)			(3,303,500)
Stock repurchases			$ (99,942)				(99,942)		(99,942)
Redemption value adjustment
Net unrealized gain (loss) on derivatives						535	535		535	535
Foreign currency translation adjustment						(18,545)	(18,545)	13	(18,532)	(18,545)
Common stock issued under equity incentive plans, net of shares withheld for employee taxes and strike price (in shares)	678,812
Common stock issued under equity incentive plans, net of shares withheld for employee taxes and strike price	$ 6	(11,473)					(11,467)		(11,467)
Net share settlement of restricted stock awards (in shares)			(28,593)
Net share settlement of restricted stock awards			$ (949)				(949)		(949)
Excess tax benefits from equity awards		7,920					7,920		7,920
Share-based compensation		9,493					9,493		9,493
Pension liability adjustment						322	322		322	322
Net income attributable to Generac Holdings Inc.					98,788		98,788	(76)	98,712	98,788
Balance (in shares) at Dec. 31, 2016	70,261,481		(7,564,874)
Balance at Dec. 31, 2016	$ 702	449,049	$ (262,402)	(202,116)	456,052	(40,163)	401,122	(10)	401,112	401,122
Stock repurchases (in shares)			(3,968,706)
Stock repurchases			$ (149,937)				(149,937)		(149,937)
Acquisition of business								53	53
Redemption value adjustment					$ (909)		$ (909)		$ (909)	$ (909)