Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2015

Fair Value Disclosures [Abstract]

Financial Instruments Measured at Fair Value on a Recurring Basis

Financial instruments measured at fair value on a recurring basis as of March 31, 2015 and December 31, 2014 are as follows (in millions):

	As of March 31, 2015						As of December 31, 2014
	Level 1		Level 2 and 3		Total		Level 1		Level 2 and 3		Total
Assets at fair value:
Long-term investment in equity securities	$	309	$	—	$	309	$	379	$	—	$	379
U.S. Treasury securities	436		—		436		374		—		374
Mutual Funds	24		—		24		27		—		27
Total assets at fair value	$	769	$	—	$	769	$	780	$	—	$	780