EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions	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
Numerator:
Net income attributable to Franklin Electric Co., Inc.	$ 19,800	$ 33,900	$ 32,700	$ 9,100	$ 24,200	$ 30,000	$ 30,500	$ 21,200	$ 95,483	$ 105,877	$ 78,180
Less: Earnings allocated to participating securities									700	800	600
Net income available to common shareholders									$ 94,800	$ 105,100	$ 77,600
Denominator:
Basic weighted average common shares outstanding (in shares)									46.4	46.6	46.5
Effect of dilutive securities:
Non-participating employee stock options and performance awards (in shares)									0.4	0.4	0.5
Diluted weighted average common shares outstanding (in shares)									46.8	47.0	47.0
Basic earnings per share (in dollars per share)	$ 0.42	$ 0.73	$ 0.70	$ 0.19	$ 0.51	$ 0.64	$ 0.65	$ 0.45	$ 2.04	$ 2.25	$ 1.67
Diluted earnings per share (in dollars per share)	$ 0.42	$ 0.72	$ 0.70	$ 0.19	$ 0.51	$ 0.63	$ 0.64	$ 0.45	$ 2.03	$ 2.23	$ 1.65
Anti-dilutive stock options (in shares)									0.2	0.1	0.3