Segment Information Segment Reporting, by Products and Services (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Net Sales from External Customer [Line Items]
Net Sales	$ 2,601.0	$ 2,623.3	$ 2,584.7	$ 2,319.2	$ 2,479.3	$ 2,581.4	$ 2,412.1	$ 2,129.6	$ 10,128.2		$ 9,602.4		$ 8,801.2
Net Sales, by Product and Service, Percentage									100.00%		100.00%		100.00%
Notebooks/Mobile Devices [Member]
Net Sales from External Customer [Line Items]
Net Sales									1,470.8		1,333.8		1,142.6
Net Sales, by Product and Service, Percentage									14.50%		13.90%		13.00%
NetComm Products [Member]
Net Sales from External Customer [Line Items]
Net Sales									1,350.6		1,241.4		1,142.0
Net Sales, by Product and Service, Percentage									13.30%		12.90%		13.00%
Enterprise and Data Storage (Including Drives) [Member]
Net Sales from External Customer [Line Items]
Net Sales									975.1		916.9		844.1
Net Sales, by Product and Service, Percentage									9.60%		9.50%		9.60%
Other Hardware [Member]
Net Sales from External Customer [Line Items]
Net Sales									4,111.1		4,039.2		3,783.5
Net Sales, by Product and Service, Percentage									40.60%		42.10%		43.00%
Software [Member]
Net Sales from External Customer [Line Items]
Net Sales									1,886.6		1,781.6		1,621.8
Net Sales, by Product and Service, Percentage									18.60%		18.60%		18.40%
Services [Member]
Net Sales from External Customer [Line Items]
Net Sales									285.2		254.6		214.9
Net Sales, by Product and Service, Percentage									2.80%		2.70%		2.40%
Other [Member]
Net Sales from External Customer [Line Items]
Net Sales									$ 48.8	[1]	$ 34.9	[1]	$ 52.3	[1]
Net Sales, by Product and Service, Percentage									0.60%	[1]	0.30%	[1]	0.60%	[1]

[1] Includes items such as delivery charges to customers and certain commission revenue.