Fair Value of Financial Instruments (Other Investments - Telecommunications Entities) (Narrative) (Details) - Equity Investee [Member] - Subcontracting Arrangements [Member] $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2020 USD ($)	Sep. 30, 2020 USD ($)
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Payments or expenses, related party	$ 2.7	$ 9.0
Payables, related party	$ 0.4	$ 0.4

Amount for accounts payable to related parties.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant