Debt, revolving credit facilities (Details) $ in Millions		6 Months Ended
		Jun. 30, 2016 USD ($)	Jul. 01, 2019
Revolving credit
Maximum borrowing capacity		$ 300
Letters of credit outstanding		17
Amount available for use		$ 283
Illustrative borrowing rate: One-month London InterBank Offered Rate ("LIBOR") plus contractual spread	[1]	2.18%
Illustrative LIBOR Rate		0.43%
Contractual spread		1.75%
Commitment fees on amount available for use	[2]	0.30%
Agreement date		Jun. 15, 2016
Maturity date		Jun. 15, 2021
U.S. Cellular revolving credit facility
Revolving credit
Covenant compliance		U.S. Cellular believes it was in compliance with all of the financial and other covenants and requirements set forth in the revolving credit facility as of June 30, 2016.
New revolving credit facility
Revolving credit
Interest Coverage Ratio		3.00
Leverage Ratio		3.25
New revolving credit facility | Future period
Revolving credit
Leverage Ratio			3.00
Other assets and deferred charges | Aggregate revolving credit facility
Revolving credit
Debt issuance cost		$ 3
Other assets and deferred charges | New revolving credit facility
Revolving credit
Debt issuance cost		$ 2

[1] Borrowings under the revolving credit facility bear interest either at a LIBOR rate or at an alternative Base Rate as defined in the revolving credit agreement, plus an applicable margin, at U.S. Cellular’s option. U.S. Cellular may select a borrowing period of either one, two, three or six months (or other period of twelve months or less if requested by U.S. Cellular and approved by the lenders).

[2] The revolving credit facility has commitment fees based on the unsecured senior debt ratings assigned to U.S. Cellular by certain ratings agencies.