Marketable Securities, at Fair Value (Tables)

3 Months Ended

Mar. 31, 2012

Investments, Debt and Equity Securities [Abstract]

Schedule of Available-for-sale Securities

The amortized cost, gross unrealized gain, gross unrealized loss and fair values for available-for-sale securities by major security type are as follows:

	Amortized Cost	Gross Unrealized Gain	Gross Unrealized Loss	Fair Value
	(In $ millions)
Mutual funds	63	—	—	63
As of March 31, 2012	63	—	—	63
Mutual funds	64	—	—	64
As of December 31, 2011	64	—	—	64