Compensation Plans (Narrative) (Details) (USD $)	12 Months Ended							3 Months Ended		12 Months Ended
	Dec. 31, 2011 years	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2011 Plan 2007 [Member]	Dec. 31, 2011 Plan 1997 [Member]	Dec. 31, 2011 Nextel Plan [Member]	Dec. 31, 2011 MISOP Plan [Member]	Dec. 31, 2011 ESPP Plan [Member]	Mar. 31, 2009 ESPP Plan [Member]	Dec. 31, 2011 ESPP Plan [Member]
Shares available period increase (decrease)				10,000,000
Number of shares authorized and available				165,000,000				77,000,000		77,000,000
Outstanding restricted stock and options				56,000,000	9,000,000	3,000,000	5,000,000
Maximum Percentage of Employee compensation eligible for ESPP								20.00%		20.00%
Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Offering Date									90.00%	95.00%
ESPP Maximum Shares Per Employee										9,000
ESPP Maximum Fair Market Value Per Employee										$ 25,000
Stock Issued During Period, Shares, Employee Stock Purchase Plans								1,500,000
Stock Issued During Period Price Employee Stock Purchase Plan								$ 2.21
Pre-tax share and non-share based compensation charges	73,000,000	70,000,000	81,000,000
Tax-related benefits	13,000,000	(18,000,000)	(3,000,000)
Unrecognized compensation cost related to non-vested incentive awards	42,000,000
Weighted average period of unrecognized compensation cost related to non-vested incentive awards, years	1.60
Cash received from exercise under all share-based payment arrangements	9,000,000	7,000,000
Fair value of restricted stock units vested	$ 15,000,000	$ 40,000,000	$ 53,000,000
Restricted stock units weighted-average grant date fair value	$ 4.25	$ 3.48	$ 2.96