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

3 Months Ended

Mar. 31, 2019

Details of our investments are as follows:

	March 31, 2019						December 31, 2018
	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 debt securities:
Money market funds	$	1,073	$	—	$	—	$	747	$	—	$	—
Corporate obligations		865		266		—		473		748		—
U.S. government agency and Treasury securities		1,497		100		—		988		1,047		—
Trading securities:
Mutual funds		—		—		250		—		—		226
Total		3,435		366		250		2,208		1,795		226

Other measurement basis:
Equity-method investments		—		—		27		—		—		21
Non-marketable equity investments		—		—		4		—		—		4
Cash on hand		285		—		—		230		—		—
Total	$	3,720	$	366	$	281	$	2,438	$	1,795	$	251

Aggregate Maturities of Available-for-sale Debt Investments

The following table presents the aggregate maturities of our available-for-sale debt investments as of March 31, 2019:

	Fair Value
One year or less	$	3,644
One to two years		157

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.

	March 31, 2019						December 31, 2018
	Level 1		Level 2		Total		Level 1		Level 2		Total
Assets:
Money market funds	$	1,073	$	—	$	1,073	$	747	$	—	$	747
Corporate obligations		—		1,131		1,131		—		1,221		1,221
U.S. government agency and Treasury securities		1,597		—		1,597		2,035		—		2,035
Mutual funds		250		—		250		226		—		226
Total assets	$	2,920	$	1,131	$	4,051	$	3,008	$	1,221	$	4,229

Liabilities:
Deferred compensation	$	266	$	—	$	266	$	246	$	—	$	246
Total liabilities	$	266	$	—	$	266	$	246	$	—	$	246