Schedule II - Valuation and Qualifying Accounts

12 Months Ended

Dec. 31, 2020

Receivables [Abstract]

Schedule II - Valuation and Qualifying Accounts

Schedule II—Valuation and Qualifying Accounts

	Balance,						Balance,
	Beginning of						End of
(MILLIONS OF DOLLARS)	Period		Additions		Deductions		Period
Year Ended December 31, 2020
Allowance for doubtful accounts	$	21	$	3	$	(4)	$	20
Year Ended December 31, 2019
Allowance for doubtful accounts	$	24	$	3	$	(6)	$	21
Year Ended December 31, 2018
Allowance for doubtful accounts	$	25	$	2	$	(3)	$	24