Fair Value Measurements (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended		3 Months Ended	9 Months Ended
	Sep. 30, 2012 U.S. RadioShack Company-Operated Stores [Member]	Sep. 30, 2012 U.S. RadioShack Company-Operated Stores [Member] Minimum [Member]	Sep. 30, 2012 U.S. RadioShack Company-Operated Stores [Member] Maximum [Member]	Sep. 30, 2012 Target Mobile Centers [Member]	Sep. 30, 2012 Target Mobile Centers [Member]	Sep. 30, 2012 2013 Convertible Notes [Member]	Dec. 31, 2011 2013 Convertible Notes [Member]	Sep. 30, 2012 2019 Notes [Member]	Dec. 31, 2011 2019 Notes [Member]	May 03, 2011 2019 Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying value of long-lived assets before impairment	$ 2.4			$ 12.8
Fair value of long-lived assets after impairment	0.6			1.1	1.1
Long-lived assets impairment charge	1.8			11.7	11.7
Risk-adjusted rate of return		15.00%	20.00%
Interest rate of debt instrument						2.50%				6.75%
Fair values of debt instruments						$ 266.5	$ 358.6	$ 189.3	$ 281.4