Segment Information Segment Reporting, by Products and Services (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Net Sales from External Customer [Line Items]
Net Sales	$ 2,713.3	$ 2,864.3	$ 2,779.3	$ 2,411.7	$ 2,601.0	$ 2,623.3	$ 2,584.7	$ 2,319.2	$ 10,768.6		$ 10,128.2		$ 9,602.4
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									1,706.0		1,470.1		1,336.9
Net Sales, by Product and Service, Percentage									15.80%		14.50%		13.90%
NetComm Products [Member]
Net Sales from External Customer [Line Items]
Net Sales									1,489.1		1,351.1		1,237.7
Net Sales, by Product and Service, Percentage									13.80%		13.30%		12.90%
Enterprise and Data Storage (Including Drives) [Member]
Net Sales from External Customer [Line Items]
Net Sales									998.1		979.4		929.9
Net Sales, by Product and Service, Percentage									9.30%		9.70%		9.70%
Other Hardware [Member]
Net Sales from External Customer [Line Items]
Net Sales									4,173.3		4,068.8		3,988.3
Net Sales, by Product and Service, Percentage									38.80%		40.20%		41.50%
Software [Member]
Net Sales from External Customer [Line Items]
Net Sales									1,994.7		1,849.4		1,767.2
Net Sales, by Product and Service, Percentage									18.50%		18.30%		18.40%
Services [Member]
Net Sales from External Customer [Line Items]
Net Sales									327.1		284.6		254.3
Net Sales, by Product and Service, Percentage									3.00%		2.80%		2.60%
Other [Member]
Net Sales from External Customer [Line Items]
Net Sales									80.3	[1]	124.8	[1]	88.1	[1]
Net Sales, by Product and Service, Percentage									0.80%	[1]	1.20%	[1]	1.00%	[1]
Public [Member]
Net Sales from External Customer [Line Items]
Net Sales	990.5	1,244.6	1,082.6	846.8	1,001.3	1,163.7	1,040.4	817.6	4,164.5		4,023.0		3,757.2
Federal [Member] | Public [Member]
Net Sales from External Customer [Line Items]
Net Sales									$ 764.4		$ 964.7		$ 953.6

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