Details of Certain Balance Sheet Accounts (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Receivables, net [Abstract]
Trade accounts	$ 85,321	$ 80,705
Vendor incentives	29,373	24,727
Other, net	1,761	3,213
Total receivables	116,455	108,645
Less allowance for doubtful accounts	(5,900)	(7,102)
Receivables, net	110,555	101,543
Prepaid expenses and other current assets [Abstract]
Prepaid expenses	7,527	7,354
Other current assets	3,771	324
Prepaid expenses and other current assets	11,298	7,678
Property and equipment, net [Abstract]
Land	1,641	1,641
Building	2,188	2,250
Leasehold improvements	24,820	21,825
Autos and trucks	7,099	1,929
Machinery and equipment	24,433	22,161
Computer equipment	31,616	27,835
Furniture and fixtures	7,480	6,608
Fixed assets in progress	2,000	1,962
Total property and equipment	101,277	86,211
Less accumulated depreciation	(59,883)	(55,526)
Property and equipment, net	41,394	30,685
Other assets, net [Abstract]
Non-current deferred tax assets, net	22,457	22,779
Other, net	6,949	6,042
Other assets, net	29,406	28,821
Accrued expenses and other current liabilities [Abstract]
Salaries and bonuses	36,141	20,705
Current deferred tax liabilities	2,976	3,226
Other	14,281	17,773
Accrued expenses and other current liabilities	$ 53,398	$ 41,704