XML 60 R49.htm IDEA: XBRL DOCUMENT v3.10.0.1
Segment Information - Disaggregation of Revenue (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2018
Sep. 30, 2017
Sep. 30, 2018
Sep. 30, 2017
Disaggregation of Revenue [Line Items]        
Net sales $ 4,373.2 $ 3,933.2 $ 12,165.7 $ 11,080.8
Revenue net, by Product and Service, Percentage 100.00% 100.00% 100.00% 100.00%
Operating Segments | Corporate        
Disaggregation of Revenue [Line Items]        
Net sales $ 1,706.5 $ 1,552.8 $ 5,006.1 $ 4,573.5
Operating Segments | Small Business        
Disaggregation of Revenue [Line Items]        
Net sales 340.0 305.4 997.1 912.4
Operating Segments | Public        
Disaggregation of Revenue [Line Items]        
Net sales 1,875.1 1,693.9 4,740.5 4,480.4
Operating Segments | Other        
Disaggregation of Revenue [Line Items]        
Net sales 451.6 381.1 1,422.0 1,114.5
Transferred at a point in time where CDW is principal        
Disaggregation of Revenue [Line Items]        
Net sales 4,060.0 3,650.7 11,244.5 10,251.9
Transferred at a point in time where CDW is principal | Operating Segments | Corporate        
Disaggregation of Revenue [Line Items]        
Net sales 1,571.6 1,423.9 4,581.3 4,176.1
Transferred at a point in time where CDW is principal | Operating Segments | Small Business        
Disaggregation of Revenue [Line Items]        
Net sales 321.0 289.1 940.0 861.5
Transferred at a point in time where CDW is principal | Operating Segments | Public        
Disaggregation of Revenue [Line Items]        
Net sales 1,764.6 1,597.3 4,445.8 4,217.0
Transferred at a point in time where CDW is principal | Operating Segments | Other        
Disaggregation of Revenue [Line Items]        
Net sales 402.8 340.4 1,277.4 997.3
Transferred at a point in time where CDW is agent        
Disaggregation of Revenue [Line Items]        
Net sales 179.2 158.1 528.2 466.5
Transferred at a point in time where CDW is agent | Operating Segments | Corporate        
Disaggregation of Revenue [Line Items]        
Net sales 85.7 82.2 279.9 256.0
Transferred at a point in time where CDW is agent | Operating Segments | Small Business        
Disaggregation of Revenue [Line Items]        
Net sales 16.9 14.4 50.5 44.3
Transferred at a point in time where CDW is agent | Operating Segments | Public        
Disaggregation of Revenue [Line Items]        
Net sales 64.3 53.5 160.7 143.1
Transferred at a point in time where CDW is agent | Operating Segments | Other        
Disaggregation of Revenue [Line Items]        
Net sales 12.3 8.0 37.1 23.1
Transferred over time where CDW is principal        
Disaggregation of Revenue [Line Items]        
Net sales 134.0 124.4 393.0 362.4
Transferred over time where CDW is principal | Operating Segments | Corporate        
Disaggregation of Revenue [Line Items]        
Net sales 49.2 46.7 144.9 141.4
Transferred over time where CDW is principal | Operating Segments | Small Business        
Disaggregation of Revenue [Line Items]        
Net sales 2.1 1.9 6.6 6.6
Transferred over time where CDW is principal | Operating Segments | Public        
Disaggregation of Revenue [Line Items]        
Net sales 46.2 43.1 134.0 120.3
Transferred over time where CDW is principal | Operating Segments | Other        
Disaggregation of Revenue [Line Items]        
Net sales 36.5 32.7 107.5 94.1
Corporate        
Disaggregation of Revenue [Line Items]        
Net sales 1,706.5 1,552.8 5,006.1 4,573.5
Corporate | Operating Segments | Corporate        
Disaggregation of Revenue [Line Items]        
Net sales 1,706.5 1,552.8 5,006.1 4,573.5
Corporate | Operating Segments | Small Business        
Disaggregation of Revenue [Line Items]        
Net sales 0.0 0.0 0.0 0.0
Corporate | Operating Segments | Public        
Disaggregation of Revenue [Line Items]        
Net sales 0.0 0.0 0.0 0.0
Corporate | Operating Segments | Other        
Disaggregation of Revenue [Line Items]        
Net sales 0.0 0.0 0.0 0.0
Small Business        
Disaggregation of Revenue [Line Items]        
Net sales 340.0 305.4 997.1 912.4
Small Business | Operating Segments | Corporate        
Disaggregation of Revenue [Line Items]        
Net sales 0.0 0.0 0.0 0.0
Small Business | Operating Segments | Small Business        
Disaggregation of Revenue [Line Items]        
Net sales 340.0 305.4 997.1 912.4
Small Business | Operating Segments | Public        
Disaggregation of Revenue [Line Items]        
Net sales 0.0 0.0 0.0 0.0
Small Business | Operating Segments | Other        
Disaggregation of Revenue [Line Items]        
Net sales 0.0 0.0 0.0 0.0
Government        
Disaggregation of Revenue [Line Items]        
Net sales 639.3 591.9 1,551.3 1,490.0
Government | Operating Segments | Corporate        
Disaggregation of Revenue [Line Items]        
Net sales 0.0 0.0 0.0 0.0
Government | Operating Segments | Small Business        
Disaggregation of Revenue [Line Items]        
Net sales 0.0 0.0 0.0 0.0
Government | Operating Segments | Public        
Disaggregation of Revenue [Line Items]        
Net sales 639.3 591.9 1,551.3 1,490.0
Government | Operating Segments | Other        
Disaggregation of Revenue [Line Items]        
Net sales 0.0 0.0 0.0 0.0
Education        
Disaggregation of Revenue [Line Items]        
Net sales 793.1 691.3 1,902.4 1,789.3
Education | Operating Segments | Corporate        
Disaggregation of Revenue [Line Items]        
Net sales 0.0 0.0 0.0 0.0
Education | Operating Segments | Small Business        
Disaggregation of Revenue [Line Items]        
Net sales 0.0 0.0 0.0 0.0
Education | Operating Segments | Public        
Disaggregation of Revenue [Line Items]        
Net sales 793.1 691.3 1,902.4 1,789.3
Education | Operating Segments | Other        
Disaggregation of Revenue [Line Items]        
Net sales 0.0 0.0 0.0 0.0
Healthcare        
Disaggregation of Revenue [Line Items]        
Net sales 442.7 410.7 1,286.8 1,201.1
Healthcare | Operating Segments | Corporate        
Disaggregation of Revenue [Line Items]        
Net sales 0.0 0.0 0.0 0.0
Healthcare | Operating Segments | Small Business        
Disaggregation of Revenue [Line Items]        
Net sales 0.0 0.0 0.0 0.0
Healthcare | Operating Segments | Public        
Disaggregation of Revenue [Line Items]        
Net sales 442.7 410.7 1,286.8 1,201.1
Healthcare | Operating Segments | Other        
Disaggregation of Revenue [Line Items]        
Net sales 0.0 0.0 0.0 0.0
Other        
Disaggregation of Revenue [Line Items]        
Net sales 451.6 381.1 1,422.0 1,114.5
Other | Operating Segments | Corporate        
Disaggregation of Revenue [Line Items]        
Net sales 0.0 0.0 0.0 0.0
Other | Operating Segments | Small Business        
Disaggregation of Revenue [Line Items]        
Net sales 0.0 0.0 0.0 0.0
Other | Operating Segments | Public        
Disaggregation of Revenue [Line Items]        
Net sales 0.0 0.0 0.0 0.0
Other | Operating Segments | Other        
Disaggregation of Revenue [Line Items]        
Net sales 451.6 381.1 1,422.0 1,114.5
Notebooks/Mobile Devices        
Disaggregation of Revenue [Line Items]        
Net sales $ 1,114.7 $ 964.8 $ 3,041.7 $ 2,612.1
Revenue net, by Product and Service, Percentage 25.50% 24.50% 25.00% 23.60%
Netcomm Products        
Disaggregation of Revenue [Line Items]        
Net sales $ 581.4 $ 544.1 $ 1,562.9 $ 1,543.5
Revenue net, by Product and Service, Percentage 13.30% 13.80% 12.80% 13.90%
Desktops        
Disaggregation of Revenue [Line Items]        
Net sales $ 341.6 $ 306.2 $ 990.4 $ 877.6
Revenue net, by Product and Service, Percentage 7.80% 7.80% 8.10% 7.90%
Video        
Disaggregation of Revenue [Line Items]        
Net sales $ 319.5 $ 290.7 $ 904.5 $ 815.7
Revenue net, by Product and Service, Percentage 7.30% 7.40% 7.40% 7.40%
Enterprise and Data Storage (Including Drives)        
Disaggregation of Revenue [Line Items]        
Net sales $ 293.2 $ 281.2 $ 813.7 $ 806.9
Revenue net, by Product and Service, Percentage 6.70% 7.10% 6.70% 7.30%
Other Hardware        
Disaggregation of Revenue [Line Items]        
Net sales $ 908.3 $ 814.8 $ 2,539.8 $ 2,307.0
Revenue net, by Product and Service, Percentage 20.80% 20.80% 21.00% 20.80%
Hardware        
Disaggregation of Revenue [Line Items]        
Net sales $ 3,558.7 $ 3,201.8 $ 9,853.0 $ 8,962.8
Revenue net, by Product and Service, Percentage 81.40% 81.40% 81.00% 80.90%
Hardware | Operating Segments | Corporate        
Disaggregation of Revenue [Line Items]        
Net sales $ 1,378.1 $ 1,253.9 $ 4,010.5 $ 3,639.8
Hardware | Operating Segments | Small Business        
Disaggregation of Revenue [Line Items]        
Net sales 284.0 256.9 830.7 758.6
Hardware | Operating Segments | Public        
Disaggregation of Revenue [Line Items]        
Net sales 1,531.5 1,383.9 3,877.5 3,671.9
Hardware | Operating Segments | Other        
Disaggregation of Revenue [Line Items]        
Net sales 365.1 307.1 1,134.3 892.5
Software        
Disaggregation of Revenue [Line Items]        
Net sales $ 607.6 $ 544.2 $ 1,718.4 $ 1,580.5
Revenue net, by Product and Service, Percentage 13.90% 13.80% 14.10% 14.30%
Software | Operating Segments | Corporate        
Disaggregation of Revenue [Line Items]        
Net sales $ 228.5 $ 202.7 $ 702.3 $ 647.2
Software | Operating Segments | Small Business        
Disaggregation of Revenue [Line Items]        
Net sales 44.3 37.9 130.0 120.4
Software | Operating Segments | Public        
Disaggregation of Revenue [Line Items]        
Net sales 290.8 265.3 729.7 692.3
Software | Operating Segments | Other        
Disaggregation of Revenue [Line Items]        
Net sales 44.0 38.3 156.4 120.6
Services        
Disaggregation of Revenue [Line Items]        
Net sales $ 178.6 $ 157.9 $ 508.6 $ 452.1
Revenue net, by Product and Service, Percentage 4.10% 4.00% 4.20% 4.10%
Services | Operating Segments | Corporate        
Disaggregation of Revenue [Line Items]        
Net sales $ 83.2 $ 79.2 $ 242.6 $ 236.3
Services | Operating Segments | Small Business        
Disaggregation of Revenue [Line Items]        
Net sales 6.6 5.5 20.6 18.0
Services | Operating Segments | Public        
Disaggregation of Revenue [Line Items]        
Net sales 48.3 39.5 120.5 102.2
Services | Operating Segments | Other        
Disaggregation of Revenue [Line Items]        
Net sales 40.5 33.7 124.9 95.6
Other        
Disaggregation of Revenue [Line Items]        
Net sales $ 28.3 $ 29.3 $ 85.7 $ 85.4
Revenue net, by Product and Service, Percentage 0.60% 0.80% 0.70% 0.70%
Other | Operating Segments | Corporate        
Disaggregation of Revenue [Line Items]        
Net sales $ 16.7 $ 17.0 $ 50.7 $ 50.2
Other | Operating Segments | Small Business        
Disaggregation of Revenue [Line Items]        
Net sales 5.1 5.1 15.8 15.4
Other | Operating Segments | Public        
Disaggregation of Revenue [Line Items]        
Net sales 4.5 5.2 12.8 14.0
Other | Operating Segments | Other        
Disaggregation of Revenue [Line Items]        
Net sales 2.0 2.0 6.4 5.8
United States        
Disaggregation of Revenue [Line Items]        
Net sales 3,926.0 3,556.5 10,761.5 9,981.3
United States | Operating Segments | Corporate        
Disaggregation of Revenue [Line Items]        
Net sales 1,704.1 1,551.2 4,999.9 4,569.3
United States | Operating Segments | Small Business        
Disaggregation of Revenue [Line Items]        
Net sales 340.0 305.4 997.1 912.4
United States | Operating Segments | Public        
Disaggregation of Revenue [Line Items]        
Net sales 1,875.1 1,693.9 4,740.5 4,480.4
United States | Operating Segments | Other        
Disaggregation of Revenue [Line Items]        
Net sales 6.8 6.0 24.0 19.2
Rest of World        
Disaggregation of Revenue [Line Items]        
Net sales 447.2 376.7 1,404.2 1,099.5
Rest of World | Operating Segments | Corporate        
Disaggregation of Revenue [Line Items]        
Net sales 2.4 1.6 6.2 4.2
Rest of World | Operating Segments | Small Business        
Disaggregation of Revenue [Line Items]        
Net sales 0.0 0.0 0.0 0.0
Rest of World | Operating Segments | Public        
Disaggregation of Revenue [Line Items]        
Net sales 0.0 0.0 0.0 0.0
Rest of World | Operating Segments | Other        
Disaggregation of Revenue [Line Items]        
Net sales $ 444.8 $ 375.1 $ 1,398.0 $ 1,095.3