Labor Union Contracts	12 Months Ended
Dec. 31, 2020
Risks and Uncertainties [Abstract]
Labor Union Contracts	Labor Union ContractsAs of December 31, 2020, approximately 23% of our employees were represented by the Communication Workers of America ("CWA") or the International Brotherhood of Electrical Workers ("IBEW"). We believe that relations with our employees continue to be generally good. Approximately 1% of our union-represented employees were subject to collective bargaining agreements that expired as of December 31, 2020 and are currently being renegotiated. Approximately 14% of our represented employees are subject to collective bargaining agreements that are scheduled to expire over the 12 month period ending December 31, 2021.

The entire disclosure for any concentrations existing at the date of the financial statements that make an entity vulnerable to a reasonably possible, near-term, severe impact. This disclosure informs financial statement users about the general nature of the risk associated with the concentration, and may indicate the percentage of concentration risk as of the balance sheet date.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-URI http://asc.fasb.org/topic&trid=2134479

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