v2.4.1.9

Selected Quarterly Financial Results (Details) (USD $)

3 Months Ended

12 Months Ended

Dec. 31, 2014

Sep. 30, 2014

Jun. 30, 2014

Mar. 31, 2014

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2012

IPO Related Expenses

$ 74,100,000cdw_IPORelatedExpenses

Revenue, Net

3,050,100,000us-gaap_SalesRevenueNet

3,266,100,000us-gaap_SalesRevenueNet

3,106,000,000us-gaap_SalesRevenueNet

2,652,300,000us-gaap_SalesRevenueNet

2,713,300,000us-gaap_SalesRevenueNet

2,864,300,000us-gaap_SalesRevenueNet

2,779,300,000us-gaap_SalesRevenueNet

2,411,700,000us-gaap_SalesRevenueNet

12,074,500,000us-gaap_SalesRevenueNet

10,768,600,000us-gaap_SalesRevenueNet

10,128,200,000us-gaap_SalesRevenueNet

Gross Profit

491,900,000us-gaap_GrossProfit

507,300,000us-gaap_GrossProfit

496,900,000us-gaap_GrossProfit

425,200,000us-gaap_GrossProfit

448,300,000us-gaap_GrossProfit

458,400,000us-gaap_GrossProfit

451,600,000us-gaap_GrossProfit

402,000,000us-gaap_GrossProfit

1,921,300,000us-gaap_GrossProfit

1,760,300,000us-gaap_GrossProfit

1,669,600,000us-gaap_GrossProfit

Income (loss) from operations

164,300,000us-gaap_OperatingIncomeLoss

184,700,000us-gaap_OperatingIncomeLoss

188,200,000us-gaap_OperatingIncomeLoss

135,800,000us-gaap_OperatingIncomeLoss

142,000,000us-gaap_OperatingIncomeLoss

^[1]

92,900,000us-gaap_OperatingIncomeLoss

^[1]

153,600,000us-gaap_OperatingIncomeLoss

^[1]

120,100,000us-gaap_OperatingIncomeLoss

^[1]

673,000,000us-gaap_OperatingIncomeLoss

508,600,000us-gaap_OperatingIncomeLoss

^[2]

510,600,000us-gaap_OperatingIncomeLoss

Net income (loss)

51,800,000us-gaap_NetIncomeLoss

55,600,000us-gaap_NetIncomeLoss

86,600,000us-gaap_NetIncomeLoss

50,900,000us-gaap_NetIncomeLoss

60,000,000us-gaap_NetIncomeLoss

^[1]

(2,200,000)us-gaap_NetIncomeLoss

^[1]

46,700,000us-gaap_NetIncomeLoss

^[1]

28,300,000us-gaap_NetIncomeLoss

^[1]

244,900,000us-gaap_NetIncomeLoss

132,800,000us-gaap_NetIncomeLoss

119,000,000us-gaap_NetIncomeLoss

Basic

$ 0.30us-gaap_EarningsPerShareBasic

^[3]

$ 0.33us-gaap_EarningsPerShareBasic

^[3]

$ 0.51us-gaap_EarningsPerShareBasic

^[3]

$ 0.30us-gaap_EarningsPerShareBasic

^[3]

$ 0.35us-gaap_EarningsPerShareBasic

^[1],[3]

$ (0.01)us-gaap_EarningsPerShareBasic

^[1],[3]

$ 0.32us-gaap_EarningsPerShareBasic

^[1],[3]

$ 0.19us-gaap_EarningsPerShareBasic

^[1],[3]

$ 1.44us-gaap_EarningsPerShareBasic

$ 0.85us-gaap_EarningsPerShareBasic

$ 0.82us-gaap_EarningsPerShareBasic

Diluted

$ 0.30us-gaap_EarningsPerShareDiluted

^[3]

$ 0.32us-gaap_EarningsPerShareDiluted

^[3]

$ 0.50us-gaap_EarningsPerShareDiluted

^[3]

$ 0.30us-gaap_EarningsPerShareDiluted

^[3]

$ 0.35us-gaap_EarningsPerShareDiluted

^[1],[3]

$ (0.01)us-gaap_EarningsPerShareDiluted

^[1],[3]

$ 0.32us-gaap_EarningsPerShareDiluted

^[1],[3]

$ 0.19us-gaap_EarningsPerShareDiluted

^[1],[3]

$ 1.42us-gaap_EarningsPerShareDiluted

$ 0.84us-gaap_EarningsPerShareDiluted

$ 0.82us-gaap_EarningsPerShareDiluted

Corporate [Member]

Revenue, Net

1,691,000,000us-gaap_SalesRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_CorporateSegmentMember

1,622,700,000us-gaap_SalesRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_CorporateSegmentMember

1,656,200,000us-gaap_SalesRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_CorporateSegmentMember

1,505,600,000us-gaap_SalesRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_CorporateSegmentMember

1,553,000,000us-gaap_SalesRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_CorporateSegmentMember

1,465,800,000us-gaap_SalesRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_CorporateSegmentMember

1,537,400,000us-gaap_SalesRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_CorporateSegmentMember

1,403,900,000us-gaap_SalesRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_CorporateSegmentMember

Corporate [Member] | Medium/Large [Member]

Revenue, Net

1,440,300,000us-gaap_SalesRevenueNet
/ cdw_CorporateAxis
= cdw_MediumLargeMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_CorporateSegmentMember

1,374,800,000us-gaap_SalesRevenueNet
/ cdw_CorporateAxis
= cdw_MediumLargeMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_CorporateSegmentMember

1,395,400,000us-gaap_SalesRevenueNet
/ cdw_CorporateAxis
= cdw_MediumLargeMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_CorporateSegmentMember

1,274,800,000us-gaap_SalesRevenueNet
/ cdw_CorporateAxis
= cdw_MediumLargeMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_CorporateSegmentMember

1,322,300,000us-gaap_SalesRevenueNet
/ cdw_CorporateAxis
= cdw_MediumLargeMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_CorporateSegmentMember

^[4]

1,241,300,000us-gaap_SalesRevenueNet
/ cdw_CorporateAxis
= cdw_MediumLargeMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_CorporateSegmentMember

^[4]

1,308,500,000us-gaap_SalesRevenueNet
/ cdw_CorporateAxis
= cdw_MediumLargeMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_CorporateSegmentMember

^[4]

1,180,500,000us-gaap_SalesRevenueNet
/ cdw_CorporateAxis
= cdw_MediumLargeMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_CorporateSegmentMember

^[4]

Corporate [Member] | Small Business [Member]

Revenue, Net

250,700,000us-gaap_SalesRevenueNet
/ cdw_CorporateAxis
= cdw_SmallBusinessMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_CorporateSegmentMember

247,900,000us-gaap_SalesRevenueNet
/ cdw_CorporateAxis
= cdw_SmallBusinessMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_CorporateSegmentMember

260,800,000us-gaap_SalesRevenueNet
/ cdw_CorporateAxis
= cdw_SmallBusinessMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_CorporateSegmentMember

230,800,000us-gaap_SalesRevenueNet
/ cdw_CorporateAxis
= cdw_SmallBusinessMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_CorporateSegmentMember

230,700,000us-gaap_SalesRevenueNet
/ cdw_CorporateAxis
= cdw_SmallBusinessMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_CorporateSegmentMember

^[4]

224,500,000us-gaap_SalesRevenueNet
/ cdw_CorporateAxis
= cdw_SmallBusinessMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_CorporateSegmentMember

^[4]

228,900,000us-gaap_SalesRevenueNet
/ cdw_CorporateAxis
= cdw_SmallBusinessMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_CorporateSegmentMember

^[4]

223,400,000us-gaap_SalesRevenueNet
/ cdw_CorporateAxis
= cdw_SmallBusinessMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_CorporateSegmentMember

^[4]

Public [Member]

Revenue, Net

1,169,100,000us-gaap_SalesRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_PublicMember

1,468,800,000us-gaap_SalesRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_PublicMember

1,271,600,000us-gaap_SalesRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_PublicMember

969,900,000us-gaap_SalesRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_PublicMember

990,500,000us-gaap_SalesRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_PublicMember

1,244,600,000us-gaap_SalesRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_PublicMember

1,082,600,000us-gaap_SalesRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_PublicMember

846,800,000us-gaap_SalesRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_PublicMember

Public [Member] | Government [Member]

Revenue, Net

440,800,000us-gaap_SalesRevenueNet
/ cdw_PublicAxis
= cdw_GovernmentSegmentMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_PublicMember

441,300,000us-gaap_SalesRevenueNet
/ cdw_PublicAxis
= cdw_GovernmentSegmentMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_PublicMember

313,100,000us-gaap_SalesRevenueNet
/ cdw_PublicAxis
= cdw_GovernmentSegmentMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_PublicMember

254,200,000us-gaap_SalesRevenueNet
/ cdw_PublicAxis
= cdw_GovernmentSegmentMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_PublicMember

327,300,000us-gaap_SalesRevenueNet
/ cdw_PublicAxis
= cdw_GovernmentSegmentMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_PublicMember

375,300,000us-gaap_SalesRevenueNet
/ cdw_PublicAxis
= cdw_GovernmentSegmentMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_PublicMember

295,700,000us-gaap_SalesRevenueNet
/ cdw_PublicAxis
= cdw_GovernmentSegmentMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_PublicMember

252,300,000us-gaap_SalesRevenueNet
/ cdw_PublicAxis
= cdw_GovernmentSegmentMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_PublicMember

Public [Member] | Education [Member]

Revenue, Net

342,600,000us-gaap_SalesRevenueNet
/ cdw_PublicAxis
= cdw_EducationMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_PublicMember

632,800,000us-gaap_SalesRevenueNet
/ cdw_PublicAxis
= cdw_EducationMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_PublicMember

527,000,000us-gaap_SalesRevenueNet
/ cdw_PublicAxis
= cdw_EducationMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_PublicMember

321,600,000us-gaap_SalesRevenueNet
/ cdw_PublicAxis
= cdw_EducationMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_PublicMember

282,800,000us-gaap_SalesRevenueNet
/ cdw_PublicAxis
= cdw_EducationMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_PublicMember

513,400,000us-gaap_SalesRevenueNet
/ cdw_PublicAxis
= cdw_EducationMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_PublicMember

420,600,000us-gaap_SalesRevenueNet
/ cdw_PublicAxis
= cdw_EducationMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_PublicMember

232,200,000us-gaap_SalesRevenueNet
/ cdw_PublicAxis
= cdw_EducationMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_PublicMember

Public [Member] | Healthcare [Member]

Revenue, Net

385,700,000us-gaap_SalesRevenueNet
/ cdw_PublicAxis
= cdw_HealthcareMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_PublicMember

394,700,000us-gaap_SalesRevenueNet
/ cdw_PublicAxis
= cdw_HealthcareMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_PublicMember

431,500,000us-gaap_SalesRevenueNet
/ cdw_PublicAxis
= cdw_HealthcareMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_PublicMember

394,100,000us-gaap_SalesRevenueNet
/ cdw_PublicAxis
= cdw_HealthcareMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_PublicMember

380,400,000us-gaap_SalesRevenueNet
/ cdw_PublicAxis
= cdw_HealthcareMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_PublicMember

355,900,000us-gaap_SalesRevenueNet
/ cdw_PublicAxis
= cdw_HealthcareMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_PublicMember

366,300,000us-gaap_SalesRevenueNet
/ cdw_PublicAxis
= cdw_HealthcareMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_PublicMember

362,300,000us-gaap_SalesRevenueNet
/ cdw_PublicAxis
= cdw_HealthcareMember
/ us-gaap_StatementBusinessSegmentsAxis
= cdw_PublicMember

Other [Member]

Revenue, Net

190,000,000us-gaap_SalesRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember

174,600,000us-gaap_SalesRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember

178,200,000us-gaap_SalesRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember

176,800,000us-gaap_SalesRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember

169,800,000us-gaap_SalesRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember

153,900,000us-gaap_SalesRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember

159,300,000us-gaap_SalesRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember

161,000,000us-gaap_SalesRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember

719,600,000us-gaap_SalesRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember

644,000,000us-gaap_SalesRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember

592,400,000us-gaap_SalesRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember

Income (loss) from operations

$ 32,900,000us-gaap_OperatingIncomeLoss
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember

$ 27,200,000us-gaap_OperatingIncomeLoss
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember

^[2]

$ 18,600,000us-gaap_OperatingIncomeLoss
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember

[1]	(3)The third quarter of 2013 included pre-tax IPO-related charges of $74.1 million. See Note 9 for additional discussion of the IPO.
[2]	(1) Includes $75.0 million of IPO- and secondary-offering related expenses, as follows: Corporate $26.4 million; Public $14.4 million; Other $3.6 million; and Headquarters $30.6 million.
[3]	(1) Basic and diluted net income (loss) per share are computed independently for each of the quarters presented. Therefore, the sum of quarterly basic and diluted per share information may not equal annual basic and diluted net income (loss) per share.
[4]	(2)Net sales for the corporate channels (medium/large and small business) have been restated for all periods presented above to conform with the new corporate hierarchy presented for first quarter of 2014.

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