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Amount of deferred income excluding obligation to transfer product and service to customer for which consideration has been received or is receivable, classified as current.

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Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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Contractual Obligation, Thereafter

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REVENUE (Details) - USD ($) $ in Millions	9 Months Ended		12 Months Ended
REVENUE (Details) - USD ($) $ in Millions	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Revenue	$ 3,064.9	$ 3,259.7	$ 4,431.2	$ 4,285.6	$ 3,879.4
current and long-term contract assets and current and long-term deferred revenue
Deferred revenue - current	189.8		160.9	170.5
Deferred revenue - noncurrent	38.9		41.3	36.5
Other contract liabilities - current			39.8	29.8
2021			21.8
2022			12.8
Thereafter			6.7
Transferred at a point in time
Disaggregation of Revenue [Line Items]
Revenue	2,247.7	2,472.3	3,348.4	3,205.9
Transferred over time
Disaggregation of Revenue [Line Items]
Revenue	817.2	787.4	1,082.8	1,079.7
Americas
Disaggregation of Revenue [Line Items]
Revenue			2,229.1	2,145.7
Americas \| Transferred at a point in time
Disaggregation of Revenue [Line Items]
Revenue			1,592.4	1,530.6
Americas \| Transferred over time
Disaggregation of Revenue [Line Items]
Revenue			636.7	615.1
Asia Pacific
Disaggregation of Revenue [Line Items]
Revenue			1,278.0	1,244.2
Asia Pacific \| Transferred at a point in time
Disaggregation of Revenue [Line Items]
Revenue			1,007.1	973.5
Asia Pacific \| Transferred over time
Disaggregation of Revenue [Line Items]
Revenue			270.9	270.7
Europe, Middle East, & Africa
Disaggregation of Revenue [Line Items]
Revenue			924.1	895.7
Europe, Middle East, & Africa \| Transferred at a point in time
Disaggregation of Revenue [Line Items]
Revenue			748.9	701.8
Europe, Middle East, & Africa \| Transferred over time
Disaggregation of Revenue [Line Items]
Revenue			175.2	193.9
Critical infrastructure & solutions
Disaggregation of Revenue [Line Items]
Revenue	$ 1,678.1	$ 1,820.4	2,632.6	2,451.8	2,136.5
Critical infrastructure & solutions \| Americas
Disaggregation of Revenue [Line Items]
Revenue			1,355.4	1,246.4
Critical infrastructure & solutions \| Asia Pacific
Disaggregation of Revenue [Line Items]
Revenue			763.2	723.9
Critical infrastructure & solutions \| Europe, Middle East, & Africa
Disaggregation of Revenue [Line Items]
Revenue			514.0	481.5
Services & software solutions
Disaggregation of Revenue [Line Items]
Revenue			1,298.9	1,276.1
Services & software solutions \| Americas
Disaggregation of Revenue [Line Items]
Revenue			679.4	669.8
Services & software solutions \| Asia Pacific
Disaggregation of Revenue [Line Items]
Revenue			336.0	339.1
Services & software solutions \| Europe, Middle East, & Africa
Disaggregation of Revenue [Line Items]
Revenue			283.5	267.2
I.T. & Edge infrastructure
Disaggregation of Revenue [Line Items]
Revenue			499.7	557.7	$ 527.0
I.T. & Edge infrastructure \| Americas
Disaggregation of Revenue [Line Items]
Revenue			194.3	229.5
I.T. & Edge infrastructure \| Asia Pacific
Disaggregation of Revenue [Line Items]
Revenue			178.8	181.2
I.T. & Edge infrastructure \| Europe, Middle East, & Africa
Disaggregation of Revenue [Line Items]
Revenue			$ 126.6	$ 147.0