SUBSEQUENT EVENTS (Details) - USD ($) $ / shares in Units, $ in Millions		1 Months Ended		3 Months Ended									12 Months Ended
	Dec. 07, 2016	Dec. 31, 2016	May 31, 2016	Jan. 31, 2017	Oct. 31, 2016	Jul. 31, 2016	Apr. 30, 2016	Jan. 31, 2016	Oct. 31, 2015	Jul. 31, 2015	Apr. 30, 2015	Jan. 31, 2015	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2015	Oct. 31, 2014
Subsequent Events
Quarterly dividend declared (in dollars per share)					$ 0.60	$ 0.60	$ 0.60	$ 0.60	$ 0.60	$ 0.60	$ 0.60	$ 0.60		$ 2.40	$ 2.40	$ 2.22
SiteOne Landscapes Supply, LLC
Partial Sale of SiteOne
Sale of interest in SiteOne (as a percent)			30.00%
Proceeds from sale of partial interest in SiteOne			$ 81
Gain on sale of partial interest, pretax			75
Gain on sale of partial interest, after-tax			$ 47
Ownership interest in SiteOne (as a percent)			24.00%		24.00%									24.00%
Voluntary Employee Separations
Voluntary Employee Separations
Total expected voluntary separation program costs, pretax					$ 111									$ 111
Incurred voluntary separation program costs, pretax					$ 11
Voluntary Employee Separations | Forecasted
Voluntary Employee Separations
Incurred voluntary separation program costs, pretax				$ 100
Voluntary separation program future savings													$ 70
Voluntary Employee Separations | Forecasted | Agriculture and Turf
Voluntary Employee Separations
Voluntary employee separation expenses allocation (as a percent)				75.00%
Voluntary Employee Separations | Forecasted | Construction and Forestry
Voluntary Employee Separations
Voluntary employee separation expenses allocation (as a percent)				17.00%
Voluntary Employee Separations | Forecasted | Financial Services
Voluntary Employee Separations
Voluntary employee separation expenses allocation (as a percent)				8.00%
Voluntary Employee Separations | Cost of Sales | Forecasted
Voluntary Employee Separations
Voluntary employee separation expenses allocation (as a percent)				30.00%
Voluntary Employee Separations | Research and Development | Forecasted
Voluntary Employee Separations
Voluntary employee separation expenses allocation (as a percent)				18.00%
Voluntary Employee Separations | Selling, Administrative, and General Expenses | Forecasted
Voluntary Employee Separations
Voluntary employee separation expenses allocation (as a percent)				52.00%
Subsequent Event
Subsequent Events
Quarterly dividend declared (in dollars per share)	$ 0.60
Subsequent Event | SiteOne Landscapes Supply, LLC
Partial Sale of SiteOne
Sale of interest in SiteOne (as a percent)		38.00%
Proceeds from sale of partial interest in SiteOne		$ 114
Gain on sale of partial interest, pretax		105
Gain on sale of partial interest, after-tax		$ 66
Ownership interest in SiteOne (as a percent)		15.00%