CONDENSED CONSOLIDATED STATEMENTS OF EARNINGS (UNAUDITED) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Net sales	$ 2,381,561	$ 2,249,275	$ 4,661,996	$ 4,442,720
Cost of merchandise sold	1,334,577	1,270,932	2,583,276	2,490,045
Gross profit	1,046,984	978,343	2,078,720	1,952,675
Warehousing, marketing and administrative expenses	696,912	664,343	1,385,344	1,334,314
Operating earnings	350,072	314,000	693,376	618,361
Other income and (expense):
Interest income	796	602	1,694	1,197
Interest expense	(3,201)	(2,910)	(6,367)	(5,967)
Other non-operating income	164	156	2,146	868
Other non-operating expense	(311)	(1,119)	(1,405)	(1,217)
Total other income and (expense)	(2,552)	(3,271)	(3,932)	(5,119)
Earnings before income taxes	347,520	310,729	689,444	613,242
Income taxes	126,767	117,628	254,164	230,683
Net earnings	220,753	193,101	435,280	382,559
Less: Net earnings attributable to noncontrolling interest	3,093	2,397	5,782	4,339
Net earnings attributable to W.W. Grainger, Inc.	$ 217,660	$ 190,704	$ 429,498	$ 378,220
Earnings per share
Basic (in dollars per share)	$ 3.08	$ 2.68	$ 6.07	$ 5.30
Diluted (in dollars per share)	$ 3.03	$ 2.63	$ 5.97	$ 5.20
Weighted average number of shares outstanding:
Basic (in shares)	69,664,697	69,937,085	69,613,947	70,034,142
Diluted (in shares)	70,801,050	71,307,640	70,788,203	71,480,677
Cash dividends paid per share (in dollars per share)	$ 0.93	$ 0.80	$ 1.73	$ 1.46