Marketable Securities and Held-to-Maturity Debt Securities (Tables)

12 Months Ended

Dec. 31, 2020

Marketable Securities and Held-to-Maturity Debt Securities

Schedule of marketable securities

(Millions)	December 31, 2020		December 31, 2019
Corporate debt securities	$	7	$	—
Commercial paper		237		85
Certificates of deposit/time deposits		31		10
U.S. treasury securities		125		—
U.S. municipal securities		4		3
Current marketable securities	$	404	$	98
U.S. municipal securities	$	30	$	43
Non-current marketable securities	$	30	$	43
Total marketable securities	$	434	$	141

Schedule of marketable securities by contractual maturity

(Millions)	December 31, 2020
Due in one year or less	$	404
Due after one year through five years		15
Due after five years through ten years		15
Total marketable securities	$	434