Earnings Per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Earnings per share
Net income (loss) attributable to U.S. Cellular shareholders	$ (22,165)	$ (9,859)	$ (21,472)	$ 138,446
Weighted average number of shares used in basic earnings per share
Weighted average number of shares used in basic earnings (loss) per share	84,233	84,005	84,262	83,897
Effects of dilutive securities:
Stock options				209
Restricted stock units				570
Weighted average number of shares used in diluted earnings (loss) per share	84,233	84,005	84,262	84,676
Earnings per share, Other disclosures
Basic earnings (loss) per share attributable to U.S. Cellular shareholders	$ (0.26)	$ (0.12)	$ (0.25)	$ 1.65
Diluted earnings (loss) per share attributable to U.S. Cellular shareholders	$ (0.26)	$ (0.12)	$ (0.25)	$ 1.64
Stock Options
Earnings per share, Other disclosures
Antidilutive securities	3,484	3,416	3,234	2,126
Restricted Stock Units
Earnings per share, Other disclosures
Antidilutive securities	1,226	1,243	1,189	305