Commitments and Contingencies (Tables)

3 Months Ended

Mar. 31, 2021

Commitments and Contingencies Disclosure [Abstract]

Lease, Cost

Components of lease expense:

	Three Months Ended March 31
(Millions of Dollars)	2021		2020
Operating leases
PPA capacity payments	$	13	$	11
Other operating leases (a)	1		1
Total operating lease expense (b)	$	14	$	12

(a)Includes immaterial short-term lease expense for 2021 and 2020.

(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 O&M expense and electric fuel and purchased power.

Lessee, Operating Lease, Liability, Maturity

Commitments under operating leases as of March 31, 2021:

(Millions of Dollars)	PPA Operating Leases		Other Operating Leases		Total Operating Leases
Total minimum obligation	$	578	$	58	$	636
Interest component of obligation	(134)		(17)		(151)
Present value of minimum obligation	$	444	$	41	485
Less current portion					(28)
Noncurrent operating and finance lease liabilities					$	457