SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Jan. 02, 2016	Oct. 03, 2015	Jul. 04, 2015	Apr. 04, 2015	Jan. 03, 2015	Sep. 27, 2014	Jun. 28, 2014	Mar. 29, 2014	Jan. 02, 2016	Jan. 03, 2015	Dec. 28, 2013
Net sales	$ 219,300	$ 232,500	$ 247,400	$ 225,700	$ 253,800	$ 278,100	$ 284,500	$ 231,400	$ 924,923	$ 1,047,777	$ 965,462
Gross profit	69,100	76,800	80,200	71,500	77,700	89,200	99,400	78,100	297,608	344,410	331,514
Net income	16,300	21,000	16,400	20,000	3,200	22,800	27,500	17,400	73,691	70,852	82,698
Net income attributable to Franklin Electric Co., Inc.	$ 16,200	$ 20,800	$ 16,100	$ 19,800	$ 3,000	$ 22,700	$ 27,100	$ 17,000	$ 72,945	$ 69,806	$ 81,958
Basic earnings per share (in dollars per share)	$ 0.34	$ 0.44	$ 0.33	$ 0.41	$ 0.06	$ 0.46	$ 0.56	$ 0.35	$ 1.52	$ 1.43	$ 1.70
Diluted earnings per share (in dollars per share)	$ 0.33	$ 0.43	$ 0.33	$ 0.41	$ 0.06	$ 0.46	$ 0.55	$ 0.35	$ 1.50	$ 1.41	$ 1.68