Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2017

Fair Value Disclosures [Abstract]

Fair Value, Assets and Liabilities Measured on Recurring Basis

Assets and liabilities measured and recorded at fair value on a recurring basis consisted of the following (in millions):

	December 31, 2017						December 31, 2016
	Total		Level 1		Level 2		Total		Level 1		Level 2
Assets
Equity securities	$	39	$	39	$	—	$	79	$	79	$	—
Mutual funds	917		917		—		856		856		—
U.S. Government securities	116		—		116		113		—		113
Other securities	170		—		170		151		—		151
Derivatives	23		—		23		27		—		27
Liabilities
Derivatives	106		—		106		85		—		85
Assets measured at NAV
Other commingled funds	19						—