Note 7 - Segment Reporting- Schedule of Error Corrections (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Net sales	$ 590,932	$ 601,135	$ 541,916	$ 470,353	$ 563,404	$ 562,388	$ 497,581	$ 400,091	$ 2,204,336	$ 2,023,464	$ 1,679,373
Adjusted EBITDA									454,115	424,552	317,300
Amounts Adjusted from the Domestic Segment to the International Segment [Member]
Net sales									13,851	13,805	31,828
Adjusted EBITDA									984	190	7,840
Residential Power Products [Member]
Net sales									1,143,723	1,042,739	870,490
Residential Power Products [Member] | Amounts Adjusted from the Domestic Segment to the International Segment [Member]
Net sales									7,129	9,924	18,888
Commercial and Industrial Power Products [Member]
Net sales									871,595	820,270	684,353
Commercial and Industrial Power Products [Member] | Amounts Adjusted from the Domestic Segment to the International Segment [Member]
Net sales									5,724	2,651	12,940
Other Products and Services [Member]
Net sales									189,018	160,455	124,530
Other Products and Services [Member] | Amounts Adjusted from the Domestic Segment to the International Segment [Member]
Net sales									$ 998	$ 1,230	$ 0