CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 26, 2020	Sep. 28, 2019	Sep. 26, 2020	Sep. 28, 2019
Statement of Comprehensive Income [Abstract]
Net Income	$ 66.3	$ 50.8	$ 142.3	$ 205.0
Other Comprehensive Income (Loss) Net of Tax:
Foreign Currency Translation Adjustments	36.7	(38.5)	(2.8)	(31.7)
Reclassification of Foreign Currency Translation Adjustments included in Net Income, Net of $0.0 Million Tax Effects for the Three Months and Nine Months Ended September 26, 2020 and September 28, 2019, Respectively	0.0	0.0	0.0	1.6
Hedging Activities:
Increase (Decrease) in Fair Value of Hedging Activities, Net of Tax Effects of $1.9 Million and $(1.6) Million for the Three Months Ended September 26, 2020 and September 28, 2019 and $(3.9) Million and $1.4 Million for the Nine Months Ended September 26, 2020 and September 28, 2019, Respectively	6.0	(4.9)	(12.3)	4.4
Reclassification of Losses (Gains) included in Net Income, Net of Tax Effects of $2.0 Million and $(1.0) Million for the Three Months Ended September 26, 2020 and September 28, 2019 and $1.9 Million and $(1.0) Million for the Nine Months Ended September 26, 2020 and September 28, 2019, Respectively	6.2	(3.2)	5.8	(3.2)
Pension and Post Retirement Plans:
Reclassification Adjustments for Pension and Post Retirement Benefits included in Net Income, Net of Tax Effects of $0.0 Million and $0.1 Million for the Three Months Ended September 26, 2020 and September 28, 2019 and $0.1 Million and $0.3 Million for the Nine Months Ended September 26, 2020 and September 28, 2019, Respectively	0.1	0.4	0.3	1.3
Other Comprehensive Income (Loss)	49.0	(46.2)	(9.0)	(27.6)
Comprehensive Income	115.3	4.6	133.3	177.4
Less: Comprehensive Income (Loss) Attributable to Noncontrolling Interests	2.2	(0.1)	3.5	1.6
Comprehensive Income Attributable to Regal Beloit Corporation	$ 113.1	$ 4.7	$ 129.8	$ 175.8