XML 45 R23.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Intangible Assets (Tables) | 3 Months Ended
--- | ---
Mar. 31, 2018
Licenses |
Licenses | Activity related to Licenses for the three months ended March 31, 2018, is presented below:
Licenses |  |
(Dollars in millions) |  |
Balance at December 31, 2017 | $ | 2,223
| Acquisitions |  | 1
| Transferred to Assets held for sale |  | (10)
| Exchanges - Licenses received |  | 18
| Exchanges - Licenses surrendered |  | (1)
Balance at March 31, 2018 | $ | 2,231

X
- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
Name: | us-gaap_IndefiniteLivedIntangibleAssetsRollForward
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of assets, excluding financial assets and goodwill, lacking physical substance and exist in perpetuity, by either major class or business segment. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 3 -Subparagraph (b),(d) -URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16373-109275 + Details
Name: | us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration