Debt (First Lien Notes) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Debt Instrument [Line Items]
Long-term Debt	$ 10,591	$ 10,425
First Lien Notes 2017 [Member]
Debt Instrument [Line Items]
Long-term Debt	1,200	1,200
First Lien Notes 2019 [Member]
Debt Instrument [Line Items]
Long-term Debt	400	400
First Lien Notes 2020 [Member]
Debt Instrument [Line Items]
Long-term Debt	1,092	1,092
First Lien Notes 2021 [Member]
Debt Instrument [Line Items]
Long-term Debt	2,000	2,000
First Lien Notes 2023 [Member]
Debt Instrument [Line Items]
Long-term Debt	1,200	1,200
Corporate Debt Securities [Member]
Debt Instrument [Line Items]
Long-term Debt	$ 5,892	$ 5,892