Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2018

Fair Value Measurements By Level For Assets Measured At Fair Value On A Recurring Basis

The following table summarizes fair value measurements by level at December 31, 2018, for assets and liabilities measured at fair value on a recurring basis ($ in millions):



	Level I		Level II		Level III		Total
Assets
Cash and cash equivalents	$	5,342	$	—	$	—	$	5,342
Investments available for sale:
U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	247	$	—	$	—	$	247
Corporate securities	—		3,146		—		3,146
Municipal securities	—		2,187		—		2,187
Asset-backed securities	—		683		—		683
Residential mortgage-backed securities	—		444		—		444
Commercial mortgage-backed securities	—		361		—		361
Total investments	$	247	$	6,821	$	—	$	7,068
Restricted deposits available for sale:
Cash and cash equivalents	$	8	$	—	$	—	$	8
Certificates of deposit	—		433		—		433
U.S. Treasury securities and obligations of U.S. government corporations and agencies	114		—		—		114
Total restricted deposits	$	122	$	433	$	—	$	555

Total assets at fair value	$	5,711	$	7,254	$	—	$	12,965

Liabilities
Other long-term liabilities:
Interest rate swap agreements	$	—	$	95	$	—	$	95
Total liabilities at fair value	$	—	$	95	$	—	$	95

The following table summarizes fair value measurements by level at December 31, 2017, for assets and liabilities measured at fair value on a recurring basis ($ in millions):



	Level I		Level II		Level III		Total
Assets
Cash and cash equivalents	$	4,072	$	—	$	—	$	4,072
Investments available for sale:
U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	195	$	—	$	—	$	195
Corporate securities	—		2,210		—		2,210
Municipal securities	—		2,087		—		2,087
Asset-backed securities	—		437		—		437
Residential mortgage-backed securities	—		332		—		332
Commercial mortgage-backed securities	—		271		—		271
Total investments	$	195	$	5,337	$	—	$	5,532
Restricted deposits available for sale:
Cash and cash equivalents	$	17	$	—	$	—	$	17
Certificates of deposit	4		—		—		4
U.S. Treasury securities and obligations of U.S. government corporations and agencies	114		—		—		114
Total restricted deposits	$	135	$	—	$	—	$	135
Other long-term assets:
Interest rate swap agreements	$	—	$	1	$	—	$	1
Total assets at fair value	$	4,402	$	5,338	$	—	$	9,740

Liabilities
Other long-term liabilities:
Interest rate swap agreements	$	—	$	72	$	—	$	72
Total liabilities at fair value	$	—	$	72	$	—	$	72