Investments and Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2019

Fair Value Disclosures [Abstract]

Financial Assets and Liabilities Measured at Fair Value on Recurring Basis

The table below presents disclosures about the fair value of financial assets and liabilities measured at fair value on a recurring basis in the Company's financial statements as of December 31 (in millions):

	2019								2018
	Total		Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3
Cash and cash equivalents	$	2,762	$	2,762	$	—	$	—	$	1,694	$	1,694	$	—	$	—
Short-term investments:
Corporate debt	1,045		—		1,045		—		1,023		—		1,023		—
Asset-backed securities	690		—		690		—		746		—		746		—
U.S. government and agency notes	124		—		124		—		108		—		108		—
Certificates of deposit placed through an account registry service ("CDARS")	35		—		35		—		75		—		75		—
Other fixed-income securities	95		—		95		—		116		—		116		—
Other investments measured at NAV	193		—		—		—		188		—		—		—
Restricted cash	106		106		—		—		105		105		—		—
Long-term investments:
Equity securities	385		385		—		—		249		249		—		—
AVH Derivative Assets	24		—		—		24		11		—		—		11

Carrying Values and Estimated Fair Values of Financial Instruments

The table below presents the carrying values and estimated fair values of financial instruments not presented in the tables above as of December 31 (in millions). Carrying amounts include any related discounts, premiums and issuance costs:

	2019										2018
	Carrying Amount		Fair Value								Carrying Amount		Fair Value
			Total		Level 1		Level 2		Level 3				Total		Level 1		Level 2		Level 3
Long-term debt	$	14,552	$	15,203	$	—	$	11,398	$	3,805	$	13,445	$	13,450	$	—	$	9,525	$	3,925