Segment Information - Schedule of Segment Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Segment Reporting Information [Line Items]
Net sales	$ 6,145.8	$ 5,146.4	$ 12,094.9	$ 9,983.9
Income (loss) from operations	435.3	369.9	822.2	693.3
Depreciation and amortization expense	(71.1)	(46.6)	(142.5)	(91.8)
Corporate
Segment Reporting Information [Line Items]
Net sales	2,660.7	1,983.3	5,288.3	3,788.9
Small Business
Segment Reporting Information [Line Items]
Net sales	500.0	482.9	1,024.0	915.6
Public
Segment Reporting Information [Line Items]
Net sales	2,243.0	2,080.7	4,276.0	4,002.4
Other
Segment Reporting Information [Line Items]
Net sales	742.1	599.5	1,506.6	1,277.0
Operating Segments | Corporate
Segment Reporting Information [Line Items]
Net sales	2,660.7	1,983.3	5,288.3	3,788.9
Income (loss) from operations	231.2	175.2	441.2	336.6
Depreciation and amortization expense	(23.6)	(3.8)	(48.6)	(7.8)
Operating Segments | Small Business
Segment Reporting Information [Line Items]
Net sales	500.0	482.9	1,024.0	915.6
Income (loss) from operations	47.0	44.0	93.7	86.8
Depreciation and amortization expense	(1.9)	(0.8)	(3.3)	(1.6)
Operating Segments | Public
Segment Reporting Information [Line Items]
Net sales	2,243.0	2,080.7	4,276.0	4,002.4
Income (loss) from operations	177.2	153.3	319.0	290.0
Depreciation and amortization expense	(16.5)	(16.1)	(32.8)	(29.5)
Operating Segments | Other
Segment Reporting Information [Line Items]
Net sales	742.1	599.5	1,506.6	1,277.0
Income (loss) from operations	27.8	23.7	64.5	51.4
Depreciation and amortization expense	(8.1)	(8.6)	(16.5)	(17.2)
Headquarters
Segment Reporting Information [Line Items]
Net sales	0.0	0.0	0.0	0.0
Income (loss) from operations	(47.9)	(26.3)	(96.2)	(71.5)
Depreciation and amortization expense	$ (21.0)	$ (17.3)	$ (41.3)	$ (35.7)