Revenue and Segment Information - Segment Information Of Revenues, Gross Profit And Operating Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Revenue from external customers	$ 5,517.9	$ 5,878.3	$ 5,543.1
Segment gross profit	2,046.2	2,305.5	2,080.2
PSG
Segment Reporting Information [Line Items]
Revenue from external customers	2,788.3	3,038.2	2,819.3
Segment gross profit	976.0	1,110.1	959.8
ASG
Segment Reporting Information [Line Items]
Revenue from external customers	1,972.3	2,071.2	1,950.9
Segment gross profit	794.8	878.3	817.8
ISG
Segment Reporting Information [Line Items]
Revenue from external customers	757.3	768.9	772.9
Segment gross profit	$ 275.4	$ 317.1	$ 302.6