Segment Data (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008	Dec. 31, 2007
Net sales:
United States	$ 10,791,303	$ 9,793,820	$ 8,935,651	$ 9,716,029	$ 9,609,225
Total net sales	12,458,877	11,207,589	10,057,512	11,015,263	10,843,195
Canada [Member]
Net sales:
Foreign Country	1,571,733	1,327,552	1,078,799	1,219,759	1,158,515
Mexico [Member]
Net sales:
Foreign Country	118,867	100,325	81,547	98,812	96,460
Other [Member]
Net sales:
Domestic and Foreign Countries	$ (23,026)	$ (14,108)	$ (38,485)	$ (19,337)	$ (21,005)