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Segment Information - Schedule of Segment Information (Details) - USD ($) $ in Millions | 3 Months Ended
--- | ---
Mar. 31, 2018 | Mar. 31, 2017
Segment Reporting Information [Line Items] |  |
Net sales | $ 3,606.4 | $ 3,256.0
Income (loss) from operations | 204.1 | 170.7
Depreciation and amortization expense | (66.6) | (64.2)
Operating Segments | Corporate |  |
Segment Reporting Information [Line Items] |  |
Net sales | 1,565.8 | 1,440.6
Income (loss) from operations | 124.8 | 112.1
Depreciation and amortization expense | (21.1) | (20.8)
Operating Segments | Small Business |  |
Segment Reporting Information [Line Items] |  |
Net sales | 327.6 | 292.0
Income (loss) from operations | 22.3 | 16.6
Depreciation and amortization expense | (5.2) | (5.1)
Operating Segments | Public |  |
Segment Reporting Information [Line Items] |  |
Net sales | 1,230.0 | 1,153.7
Income (loss) from operations | 71.7 | 60.8
Depreciation and amortization expense | (11.2) | (11.2)
Operating Segments | Other |  |
Segment Reporting Information [Line Items] |  |
Net sales | 483.0 | 369.7
Income (loss) from operations | 19.8 | 12.7
Depreciation and amortization expense | (8.8) | (7.2)
Headquarters |  |
Segment Reporting Information [Line Items] |  |
Net sales | 0.0 | 0.0
Income (loss) from operations | (34.5) | (31.5)
Depreciation and amortization expense | $ (20.3) | $ (19.9)

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