CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE EARNINGS - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
Net earnings	$ 272	$ 248	$ 534	$ 489
Other comprehensive earnings (losses):
Foreign currency translation adjustments	19	(49)	23	(25)
Postretirement benefit plan reclassification, net of tax benefit of $1, $1, $2 and $2, respectively	(2)	(3)	(5)	(6)
Total other comprehensive earnings	17	(52)	18	(31)
Comprehensive earnings, net of tax	289	196	552	458
Less: Comprehensive earnings (losses) attributable to noncontrolling interest
Net earnings	12	11	21	20
Foreign currency translation adjustments	5	(7)	3	2
Comprehensive earnings attributable to noncontrolling interest	17	4	24	22
Comprehensive earnings attributable to W.W. Grainger, Inc.	$ 272	$ 192	$ 528	$ 436

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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