Segment Information - Schedule of Segment Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Segment Reporting Information [Line Items]
Net sales	$ 5,949.1	$ 4,837.5
Income (loss) from operations	386.9	323.4
Depreciation and amortization expense	(71.4)	(45.2)
Corporate
Segment Reporting Information [Line Items]
Net sales	2,627.6	1,805.6
Small Business
Segment Reporting Information [Line Items]
Net sales	524.0	432.7
Public
Segment Reporting Information [Line Items]
Net sales	2,033.0	1,921.7
Other
Segment Reporting Information [Line Items]
Net sales	764.5	677.5
Operating Segments | Corporate
Segment Reporting Information [Line Items]
Net sales	2,627.6	1,805.6
Income (loss) from operations	210.0	161.4
Depreciation and amortization expense	(25.0)	(4.0)
Operating Segments | Small Business
Segment Reporting Information [Line Items]
Net sales	524.0	432.7
Income (loss) from operations	46.7	42.8
Depreciation and amortization expense	(1.4)	(0.8)
Operating Segments | Public
Segment Reporting Information [Line Items]
Net sales	2,033.0	1,921.7
Income (loss) from operations	141.8	136.7
Depreciation and amortization expense	(16.3)	(13.4)
Operating Segments | Other
Segment Reporting Information [Line Items]
Net sales	764.5	677.5
Income (loss) from operations	36.7	27.7
Depreciation and amortization expense	(8.4)	(8.6)
Headquarters
Segment Reporting Information [Line Items]
Net sales	0.0	0.0
Income (loss) from operations	(48.3)	(45.2)
Depreciation and amortization expense	$ (20.3)	$ (18.4)