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

12 Months Ended

Dec. 31, 2016

Details of our investments are as follows:

	December 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	$	346	$	—	$	—	$	395	$	—	$	—
Corporate obligations		107		544		—		132		285		—
U.S. government agency and Treasury securities		490		1,792		—		245		1,933		—
Trading securities:
Mutual funds		—		—		201		—		—		187
Total		943		2,336		201		772		2,218		187

Other measurement basis:
Equity-method investments		—		—		25		—		—		25
Cost-method investments		—		—		9		—		—		9
Cash on hand		211		—		—		228		—		—
Total	$	1,154	$	2,336	$	235	$	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 as of December 31, 2016:

Due	Fair Value
One year or less	$	3,254
One to two years		25

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. 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.

	December 31, 2016						December 31, 2015
	Level 1		Level 2		Total		Level 1		Level 2		Total
Assets:
Money market funds	$	346	$	—	$	346	$	395	$	—	$	395
Corporate obligations		—		651		651		—		417		417
U.S. government agency and Treasury securities		2,042		240		2,282		1,828		350		2,178
Mutual funds		201		—		201		187		—		187
Total assets	$	2,589	$	891	$	3,480	$	2,410	$	767	$	3,177

Liabilities:
Deferred compensation	$	218	$	—	$	218	$	198	$	—	$	198
Total liabilities	$	218	$	—	$	218	$	198	$	—	$	198