Quarterly Financial Information (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended				12 Months Ended
	Dec. 30, 2017	Sep. 30, 2017	Jul. 01, 2017	Apr. 01, 2017	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
Interim Period, Costs Not Allocable [Line Items]
Net Sales	$ 881.7	$ 925.4	$ 959.7	$ 878.8	$ 3,645.6	$ 3,360.3	$ 3,224.5
Gross Profit	239.7	242.6	247.4	234.9	964.6	883.6	865.0
Income from Operations	89.8	69.4	99.6	88.2	347.0	331.1	322.5
Net Income	56.5	52.7	67.3	59.3	235.8	218.1	209.3
Net Income Attributable to Regal Beloit Corporation	$ 55.6	$ 51.3	$ 65.9	$ 58.4	$ 231.2	$ 213.0	$ 203.4
Basic (in dollars per shares)	$ 1.29	$ 1.18	$ 1.51	$ 1.32	$ 5.30	$ 4.78	$ 4.55
Assuming Dilution (in dollars per share)	$ 1.28	$ 1.17	$ 1.50	$ 1.31	$ 5.26	$ 4.74	$ 4.52
Basic (in shares)	43.1	43.4	43.8	44.2	43.6	44.6	44.7
Assuming Dilution (in shares)	43.4	43.8	44.1	44.5	43.9	44.9	45.0
Goodwill Impairment					$ 9.5	$ 0.0	$ 0.0
Commercial and Industrial Systems
Interim Period, Costs Not Allocable [Line Items]
Net Sales	$ 436.7	$ 462.3	$ 469.0	$ 414.0	1,782.0	1,604.3	1,530.9
Income from Operations	32.1	35.3	30.5	29.1
Goodwill Impairment					0.0
Climate Solutions
Interim Period, Costs Not Allocable [Line Items]
Net Sales	232.2	255.4	277.3	259.9	1,024.8	990.6	960.0
Income from Operations	33.3	6.0	44.0	32.3
Goodwill Impairment					9.5
Power Transmission Solutions
Interim Period, Costs Not Allocable [Line Items]
Net Sales	212.8	207.7	213.4	204.9	838.8	$ 765.4	$ 733.6
Income from Operations	$ 24.4	$ 28.1	$ 25.1	$ 26.8
Goodwill Impairment					$ 0.0