The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-SubTopic 10
-Topic 210
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16)(a)(2))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1

Name:	us-gaap_LineOfCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Debt - Revolving Credit Agreements (Details) - USD ($) $ in Millions	Apr. 01, 2025	Mar. 31, 2025
TDS Revolving Credit Agreement
Line of Credit Facility [Line Items]
Maximum borrowing capacity		$ 400
Amount borrowed and outstanding		0
Amount available for use		399
TDS Revolving Credit Agreement \| Subsequent event \| Contingent event \| Minimum
Line of Credit Facility [Line Items]
License sale agreement amount	$ 1,100
UScellular Revolving Credit Agreement
Line of Credit Facility [Line Items]
Maximum borrowing capacity		300
Amount borrowed and outstanding		0
Amount available for use		$ 300
UScellular Revolving Credit Agreement \| Subsequent event \| Contingent event
Line of Credit Facility [Line Items]
Maximum borrowing capacity	150
UScellular Revolving Credit Agreement \| Subsequent event \| Contingent event \| Minimum
Line of Credit Facility [Line Items]
License sale agreement amount	1,100
UScellular Revolving Credit Agreement \| Subsequent event \| Contingent event \| Minimum \| Agreement amendment
Line of Credit Facility [Line Items]
License sale agreement amount	$ 500