Acquisitions - Additional Information (Detail) (USD $)				12 Months Ended											1 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Customer relationships [Member]	Dec. 31, 2011 Customer relationships [Member]	Dec. 31, 2010 Customer relationships [Member]	Dec. 31, 2012 Trademarks [Member]	Dec. 31, 2011 Trademarks [Member]	Dec. 31, 2010 Trademarks [Member]	Dec. 31, 2011 Non-competition agreements [Member]	Dec. 31, 2010 Non-competition agreements [Member]	Dec. 31, 2011 Industrial [Member] Business	Dec. 31, 2011 Electrical/Electronic Materials [Member] Business	Dec. 31, 2010 Industrial and Electrical/Electronic Materials Groups [Member] Business	May 01, 2012 Automotive [Member] Quaker City Motor Parts Co. [Member] Store
Business Acquisition [Line Items]
Payments to acquire business, net of cash acquired															$ 343,000,000
Annual revenue															300,000,000
Number of stores serviced															270
Number of stores owned															140
Companies acquired												3	1	4
Cost of acquired companies		115,600,000	90,645,000
Goodwill and other intangible assets acquired	230,000,000	78,210,000	40,247,000
Other intangible assets acquired				$ 108,000,000	$ 37,378,000	$ 16,688,000	$ 2,000,000	$ 12,100,000	$ 7,104,000	$ 650,000	$ 500,000
Weighted average amortization lives				15 years	15 years	14 years	40 years	40 years	40 years	5 years	5 years