Fair value measurements (Tables)

12 Months Ended

Dec. 31, 2019

Summary of assets and liabilities measured at fair value

The following table summarizes the types of assets and liabilities measured at fair value on a recurring basis by level within the fair value hierarchy (in millions):



	December 31, 2019								December 31, 2018
	Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
Assets:
Available-for-sale debt securities:
U.S. treasury securities	$	2,433	$	—	$	—	$	2,433	$	3,969	$	—	$	—	$	3,969
Certificates of deposit	—		3,517		—		3,517		—		4,361		—		4,361
U.S. government agencies securities	—		1,081		—		1,081		—		938		—		938
Non-U.S. government securities	—		174		—		174		—		305		—		305
Corporate debt securities	—		9,204		—		9,204		—		13,067		—		13,067
Residential mortgage and asset-backed securities	—		91		—		91		—		1,524		—		1,524
Equity securities:
Equity investment in Galapagos	3,477		—		—		3,477		622		—		—		622
Money market funds	7,069		—		—		7,069		5,305		—		—		5,305
Other publicly traded equity securities	322		—		—		322		259		—		—		259
Deferred compensation plan	171		—		—		171		124		—		—		124
Foreign currency derivative contracts	—		37		—		37		—		78		—		78
Total	$	13,472	$	14,104	$	—	$	27,576	$	10,279	$	20,273	$	—	$	30,552
Liabilities:
Deferred compensation plan	$	171	$	—	$	—	$	171	$	124	$	—	$	—	$	124
Foreign currency derivative contracts	—		8		—		8		—		1		—		1
Total	$	171	$	8	$	—	$	179	$	124	$	1	$	—	$	125

Summary of classification of Galapagos equity investment

The following table summarizes the classification of our equity investment in Galapagos in our Consolidated Balance Sheets (in millions):



	December 31, 2019		December 31, 2018
Prepaid and other current assets	$	—	$	622
Other long-term assets	3,477		—
Total	$	3,477	$	622

Summary of classification of other equity securities

The following table summarizes the classification of our other equity securities in our Consolidated Balance Sheets (in millions):



	December 31, 2019		December 31, 2018
Cash and cash equivalents	$	7,069	$	5,305
Prepaid and other current assets	319		241
Other long-term assets	174		142
Total	$	7,562	$	5,688