Commitment and Contingencies (Tables)

3 Months Ended

9 Months Ended

Sep. 30, 2023

Sep. 30, 2023

Commitments and Contingencies Disclosure [Abstract]

Lease, Cost

Components of lease expense:

	Three Months Ended Sept. 30
(Millions of Dollars)	2023		2022
Operating leases
PPA capacity payments	$	25	$	25
Other operating leases (a)	3		2
Total operating lease expense (b)	$	28	$	27

(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 consolidated statements of income. Expense for other operating leases is included in O&M expense and electric fuel and purchased power.

	Nine Months Ended Sept. 30
(Millions of Dollars)	2023		2022
Operating leases
PPA capacity payments	$	74	$	74
Other operating leases (a)	12		6
Total operating lease expense (b)	$	86	$	80

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	$	244	$	179	$	423
Interest component of obligation	(11)		(81)		(92)
Present value of minimum obligation	$	233	$	98	331
Less current portion					(98)
Noncurrent operating lease liabilities					$	233