Percentage of voting equity interests acquired at the acquisition date in the business combination.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Amount of the effect of a change in accounting principle on net income.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
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Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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Amount of the effect of a change in accounting principle on depreciation expense.

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BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017	Jan. 15, 2016
Service Life [Member]
Decrease to depreciation expense resulting from change in depreciation method	$ 17.4
Increase to net income resulting from change in depreciation method	$ 11.7
Allstream, Inc. [Member]
Business acquisition, percentage of voting interests acquired			100.00%
Fiber Optic Network [Member]
Estimated useful life in years	33 years
Fiber Optic Network [Member] \| Maximum [Member]
Estimated useful life in years		15 years
Fiber Optic Network [Member] \| Minimum [Member]
Estimated useful life in years		20 years
Building [Member]
Estimated useful life in years	45 years	39 years