Acquisitions (Detail) $ in Thousands	1 Months Ended					6 Months Ended	12 Months Ended
	Oct. 31, 2016 Location	Sep. 30, 2016 Location	Jun. 30, 2016 Location	May 31, 2016 Location	Mar. 31, 2016 Location Business	Jul. 31, 2016 Location Business	Dec. 31, 2016 USD ($) Business	Dec. 31, 2015 USD ($) Business	Dec. 31, 2014 USD ($) Business	Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)
Business Acquisition [Line Items]
Cash paid for acquisition							$ 420,000	$ 140,000	$ 270,000
Company acquired | Business							19
Net sales							$ 15,339,713	15,280,044	15,341,647	$ 14,077,843	$ 13,013,868
Goodwill and other intangible assets acquired							260,000	90,000	200,000
Customer relationships
Business Acquisition [Line Items]
Other intangible assets acquired							$ 112,000	$ 39,000	$ 82,000
Weighted average amortization lives (in years)							17 months	15 years	18 years
Trademarks
Business Acquisition [Line Items]
Other intangible assets acquired							$ 28,000		$ 28,000
Weighted average amortization lives (in years)							35 months		40 years
United States [Member]
Business Acquisition [Line Items]
Net sales							$ 12,822,320	$ 12,843,078	$ 12,565,329	11,594,713	11,299,291
Canada [Member]
Business Acquisition [Line Items]
Net sales							1,390,979	1,395,695	1,583,075	$ 1,560,799	$ 1,616,921
2016 Companies Acquired [Member]
Business Acquisition [Line Items]
Cash paid for acquisition							370,000
Net sales							$ 350,000
2015 Companies Acquired [Member]
Business Acquisition [Line Items]
Cash paid for acquisition								$ 120,000
2014 Companies Acquired [Member]
Business Acquisition [Line Items]
Cash paid for acquisition									$ 260,000
Electrical/ Electronic Materials
Business Acquisition [Line Items]
Company acquired | Business							1	1
Electrical/ Electronic Materials | 2016 Companies Acquired [Member]
Business Acquisition [Line Items]
Net sales							$ 12,000
Office Products
Business Acquisition [Line Items]
Company acquired | Business							2	3
Office Products | United States [Member]
Business Acquisition [Line Items]
Number of locations | Location			8
Office Products | Canada [Member]
Business Acquisition [Line Items]
Number of locations | Location			1
Office Products | 2016 Companies Acquired [Member]
Business Acquisition [Line Items]
Net sales							$ 200,000
Industrial
Business Acquisition [Line Items]
Company acquired | Business					2		5	4	1
Number of locations | Location	8
Industrial | 2016 Companies Acquired [Member]
Business Acquisition [Line Items]
Net sales							$ 170,000
Industrial | Epperson and Company [Member]
Business Acquisition [Line Items]
Number of locations | Location					3
Industrial | Missouri Power Transmission [Member]
Business Acquisition [Line Items]
Number of locations | Location					15
Automotive
Business Acquisition [Line Items]
Company acquired | Business						2	11	5	2
Automotive | United States [Member]
Business Acquisition [Line Items]
Number of locations | Location				6		6
Automotive | Canada [Member]
Business Acquisition [Line Items]
Number of locations | Location						20
Automotive | Australia [Member]
Business Acquisition [Line Items]
Number of locations | Location			4		21
Automotive | New Zealand [Member]
Business Acquisition [Line Items]
Number of locations | Location		15
Automotive | 2016 Companies Acquired [Member]
Business Acquisition [Line Items]
Net sales							$ 235,000