Valuation of Debt and Equity Investments and Certain Liabilities (Tables)

6 Months Ended

Jun. 30, 2015

Details of our investments are as follows:

	June 30, 2015						December 31, 2014
	Cash and Cash		Short-Term		Long-Term		Cash and Cash		Short-Term		Long-Term
	Equivalents		Investments		Investments		Equivalents		Investments		Investments
Measured at fair value:
Available-for-sale securities:
Money market funds	$	552	$	—	$	—	$	522	$	—	$	—
Corporate obligations		171		375		—		97		390		—
U.S. Government agency and Treasury securities		200		1,747		—		365		1,952		—
Trading securities:
Mutual funds		—		—		192		—		—		185
Total		923		2,122		192		984		2,342		185

Other measurement basis:
Equity-method investments		—		—		26		—		—		27
Cost-method investments		—		—		10		—		—		12
Cash on hand		261		—		—		215		—		—
Total	$	1,184	$	2,122	$	228	$	1,199	$	2,342	$	224

Aggregate Maturities of Investments in Debt Securities Classified as Available-for-sale

The following table presents the aggregate maturities of investments in debt securities classified as available for sale as of June 30, 2015:

Due	Fair Value
One year or less	$	2,975
One to two years		70

Assets and Liabilities Accounted for at Fair Value

The following are our assets and liabilities that were accounted for at fair value on a recurring basis as of June 30, 2015, and December 31, 2014. These tables do not include cash on hand, assets held by our postretirement plans, or assets and liabilities that are measured at historical cost or any basis other than fair value.

	Fair Value
	June 30,
	2015		Level 1		Level 2
Assets:
Money market funds	$	552	$	552	$	—
Corporate obligations		546		—		546
U.S. Government agency and Treasury securities		1,947		1,617		330
Mutual funds		192		192		—
Total assets	$	3,237	$	2,361	$	876

Liabilities:
Deferred compensation	$	203	$	203	$	—
Total liabilities	$	203	$	203	$	—

	Fair Value
	December 31,
	2014		Level 1		Level 2
Assets:
Money market funds	$	522	$	522	$	—
Corporate obligations		487		—		487
U.S. Government agency and Treasury securities		2,317		1,762		555
Mutual funds		185		185		—
Total assets	$	3,511	$	2,469	$	1,042

Liabilities:
Deferred compensation	$	202	$	202	$	—
Total liabilities	$	202	$	202	$	—