Commitments and Contingencies (Tables)

3 Months Ended

9 Months Ended

Sep. 30, 2023

Sep. 30, 2023

Commitments and Contingencies Disclosure [Abstract]

Lease, Cost

	Three Months Ended Sept. 30
(Millions of Dollars)	2023		2022
Operating leases
PPA capacity payments	$	13	$	13
Other operating leases (a)	1		1
Total operating lease expense (b)	$	14	$	14

(a)Includes immaterial short-term lease expense for 2023 and 2022.

(b)PPA capacity payments are included in electric fuel and purchased power on the statements of income. Expense for other operating leases is included in operating and maintenance expense and electric fuel and purchased power.

	Nine Months Ended Sept. 30
(Millions of Dollars)	2023		2022
Operating leases
PPA capacity payments	$	40	$	39
Other operating leases (a)	3		4
Total operating lease expense (b)	$	43	$	43

(a)Includes immaterial short-term lease expense for both 2023 and 2022.

(b)PPA capacity payments are included in electric fuel and purchased power on the statements of income. Expense for other operating leases is included in operating and maintenance expense and electric fuel and purchased power.

Lessee, Operating Lease, Liability, Maturity

Commitments under operating leases as of Sept. 30, 2023:

(Millions of Dollars)	PPA Operating Leases		Other Operating Leases		Total Operating Leases
Total minimum obligation	$	462	$	51	$	513
Interest component of obligation	(89)		(13)		(102)
Present value of minimum obligation	$	373	$	38	411
Less current portion					(32)
Noncurrent operating lease liabilities					$	379