Commitments And Contingencies (Narrative) (Details) (USD $) In Billions, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Mar. 31, 2012 Content liabilities [Member]	Dec. 31, 2011 Content liabilities [Member]
Long-term Purchase Commitment [Line Items]
Long-term Purchase Commitment, Amount	$ 5.0	$ 4.8
Recorded Unconditional Purchase Obligation			$ 1.1	$ 0.9