ACCUMULATED OTHER COMPREHENSIVE EARNINGS (LOSSES) (AOCE) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	$ 2,735	$ 2,160	$ 2,093
Net current period activity	(13)	(118)	(64)
Ending balance	3,441	2,735	2,160
Foreign Currency Translation and Other
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(320)	(219)
Other comprehensive earnings (loss) before reclassifications – net of tax	(11)	(101)
Amounts reclassified to net earnings	0	0
Net current period activity	(11)	(101)
Ending balance	(331)	(320)	(219)
Total
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(244)	(126)
Other comprehensive earnings (loss) before reclassifications – net of tax	0	(105)
Amounts reclassified to net earnings	(13)	(13)
Net current period activity	(13)	(118)
Ending balance	(257)	(244)	(126)
Foreign Currency Translation Attributable to Noncontrolling Interests
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(64)	(30)
Other comprehensive earnings (loss) before reclassifications – net of tax	(21)	(34)
Amounts reclassified to net earnings	0	0
Net current period activity	(21)	(34)
Ending balance	(85)	(64)	(30)
AOCE Attributable to W.W. Grainger, Inc.
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(180)	(96)	(61)
Other comprehensive earnings (loss) before reclassifications – net of tax	21	(71)
Amounts reclassified to net earnings	(13)	(13)
Net current period activity	8	(84)	(35)
Ending balance	(172)	(180)	(96)
Defined Postretirement Benefit Plan | Accumulated Defined Benefit Plans Adjustment Including Portion Attributable to Noncontrolling Interest
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	82	99
Other comprehensive earnings (loss) before reclassifications – net of tax	8	(4)
Amounts reclassified to net earnings	(13)	(13)
Net current period activity	(5)	(17)
Ending balance	77	82	99
Other Employment-related Benefit Plans | Accumulated Defined Benefit Plans Adjustment Including Portion Attributable to Noncontrolling Interest
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(6)	(6)
Other comprehensive earnings (loss) before reclassifications – net of tax	3	0
Amounts reclassified to net earnings	0	0
Net current period activity	3	0
Ending balance	$ (3)	$ (6)	$ (6)