Summary of Significant Accounting Policies (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011 Y
Property and Equipment
Useful life of property and equipment, low end of range (in years)	1
Useful life of property and equipment, high end of range (in years)	40
Carrying amount of 700 MHz wireless licenses	$ 712
Minimum
Marketable Investment Securities
The length of time an investment has been in a continuous loss position in which the decline in value would be evaluated on a case by case basis to determine if the decline in value is other-than-temporary (in months)	6
Length of time an investment has been in a continuous loss position in which the decline in value is considered other-than-temporary (in months)	9
Inventory
Useful life of rental library product (in months)	6
Business Combinations
Acquired intangible assets, average finite useful life (in years)	1
Revenue Recognition
Period of deferral for the portion of subscriber fees that are deferred	18
Maximum
Cash and Cash Equivalents
Original maturity period at the time of purchase by the entity for liquid investments classified as cash equivalents (in days)	90
Marketable Investment Securities
Length of time an investment has been in a continuous loss position in which the decline in value is considered as temporary (in months)	6
The length of time an investment has been in a continuous loss position in which the decline in value would be evaluated on a case by case basis to determine if the decline in value is other-than-temporary (in months)	9
Inventory
Useful life of rental library product (in months)	24
Business Combinations
Acquired intangible assets, average finite useful life (in years)	20
Long-Term Deferred Revenue, Distribution and Carriage Payments
Deferred upfront payment, amortization period (in years)	10
Revenue Recognition
Period of deferral for the portion of subscriber fees that are deferred	5