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

3 Months Ended

Mar. 31, 2016

Details of our investments are as follows:

	March 31, 2016						December 31, 2015
	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	$	536	$	—	$	—	$	395	$	—	$	—
Corporate obligations		146		255		—		132		285		—
U.S. Government agency and Treasury securities		370		1,264		—		245		1,933		—
Trading securities:
Mutual funds		—		—		186		—		—		187
Total		1,052		1,519		186		772		2,218		187

Other measurement basis:
Equity-method investments		—		—		25		—		—		25
Cost-method investments		—		—		9		—		—		9
Cash on hand		229		—		—		228		—		—
Total	$	1,281	$	1,519	$	220	$	1,000	$	2,218	$	221

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 at March 31, 2016:

Due	Fair Value
One year or less	$	2,541
One to two years		30

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 March 31, 2016, and December 31, 2015. 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
	March 31,
	2016		Level 1		Level 2
Assets:
Money market funds	$	536	$	536	$	—
Corporate obligations		401		—		401
U.S. Government agency and Treasury securities		1,634		1,104		530
Mutual funds		186		186		—
Total assets	$	2,757	$	1,826	$	931

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

	Fair Value
	December 31,
	2015		Level 1		Level 2
Assets:
Money market funds	$	395	$	395	$	—
Corporate obligations		417		—		417
U.S. Government agency and Treasury securities		2,178		1,828		350
Mutual funds		187		187		—
Total assets	$	3,177	$	2,410	$	767

Liabilities:
Deferred compensation	$	198	$	198	$	—
Total liabilities	$	198	$	198	$	—