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

6 Months Ended

Jun. 30, 2017

Details of our investments are as follows:

	June 30, 2017						December 31, 2016
	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	$	376	$	—	$	—	$	346	$	—	$	—
Corporate obligations		24		459		—		107		544		—
U.S. government agency and Treasury securities		550		1,385		—		490		1,792		—
Trading securities:
Mutual funds		—		—		218		—		—		201
Total		950		1,844		218		943		2,336		201

Other measurement basis:
Equity-method investments		—		—		23		—		—		25
Cost-method investments		—		—		9		—		—		9
Cash on hand		190		—		—		211		—		—
Total	$	1,140	$	1,844	$	250	$	1,154	$	2,336	$	235

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, 2017:

Due	Fair Value
One year or less	$	2,784
One to two years		10

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.

	June 30, 2017						December 31, 2016
	Level 1		Level 2		Total		Level 1		Level 2		Total
Assets:
Money market funds	$	376	$	—	$	376	$	346	$	—	$	346
Corporate obligations		—		483		483		—		651		651
U.S. government agency and Treasury securities		1,935		—		1,935		2,042		240		2,282
Mutual funds		218		—		218		201		—		201
Total assets	$	2,529	$	483	$	3,012	$	2,589	$	891	$	3,480

Liabilities:
Deferred compensation	$	234	$	—	$	234	$	218	$	—	$	218
Total liabilities	$	234	$	—	$	234	$	218	$	—	$	218