SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Net Sales	$ 316,600	$ 341,900	$ 344,000	$ 295,600	$ 288,200	$ 311,100	$ 305,300	$ 220,300	$ 1,298,129	$ 1,124,909	$ 949,856
Gross Profit	104,300	113,000	116,100	99,000	94,600	103,800	102,800	75,800	432,366	376,982	331,406
Net income	24,300	30,000	30,000	21,200	8,000	24,500	30,200	15,900	105,517	78,593	79,315
Net Income Attributable to Franklin Electric Co., Inc.	$ 24,200	$ 30,000	$ 30,500	$ 21,200	$ 8,100	$ 24,500	$ 29,900	$ 15,700	$ 105,877	$ 78,180	$ 78,745
Basic Earnings Per Share (in dollars per share)	$ 0.51	$ 0.64	$ 0.65	$ 0.45	$ 0.17	$ 0.52	$ 0.64	$ 0.33	$ 2.25	$ 1.67	$ 1.67
Diluted Earnings Per Share (in dollars per share)	$ 0.51	$ 0.63	$ 0.64	$ 0.45	$ 0.17	$ 0.52	$ 0.64	$ 0.33	$ 2.23	$ 1.65	$ 1.65