Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2021

Fair Value Disclosures [Abstract]

Fair value of assets and liabilities that are measured at fair value on a recurring basis

The following table presents the fair value at March 31, 2021 of our assets and liabilities that are measured at fair value on a recurring basis (dollars in thousands):

	Level 1		Level 2		Level 3		Other			Total
Assets
Risk management activities — derivative instruments:
Commodity contracts	$	—	$	14,353	$	15,340	$	(3,882)	(a)	$	25,811
Nuclear decommissioning trust:
Equity securities	22,160		—		—		(15,538)		(b)	6,622
U.S. commingled equity funds	—		—		—		648,199		(c)	648,199
U.S. Treasury debt	175,707		—		—		—			175,707
Corporate debt	—		143,876		—		—			143,876
Mortgage-backed securities	—		110,073		—		—			110,073
Municipal bonds	—		64,479		—		—			64,479
Other fixed income	—		10,743		—		—			10,743
Subtotal nuclear decommissioning trust	197,867		329,171		—		632,661			1,159,699
Other special use funds:
Equity securities	19,211		—		—		1,401		(b)	20,612
U.S. Treasury debt	323,589		—		—		—			323,589
Municipal bonds	—		13,305		—		—			13,305
Subtotal other special use funds	342,800		13,305		—		1,401			357,506
Total assets	$	540,667	$	356,829	$	15,340	$	630,180		$	1,543,016
Liabilities
Risk management activities — derivative instruments:
Commodity contracts	$	—	$	(11,668)	$	(924)	$	2,597	(a)	$	(9,995)

(a)Represents counterparty netting, margin, and collateral. See Note 7.

(b)Represents net pending securities sales and purchases.

(c)Valued using NAV as a practical expedient and, therefore, are not classified in the fair value hierarchy.

The following table presents the fair value at December 31, 2020 of our assets and liabilities that are measured at fair value on a recurring basis (dollars in thousands):

	Level 1		Level 2		Level 3		Other			Total
Assets
Risk management activities — derivative instruments:
Commodity contracts	$	—	$	9,016	$	4	$	(4,271)	(a)	$	4,749
Nuclear decommissioning trust:
Equity securities	29,796		—		—		(17,828)		(b)	11,968
U.S. commingled equity funds	—		—		—		610,055		(c)	610,055
U.S. Treasury debt	164,514		—		—		—			164,514
Corporate debt	—		149,509		—		—			149,509
Mortgage-backed securities	—		99,623		—		—			99,623
Municipal bonds	—		89,705		—		—			89,705
Other fixed income	—		13,061		—		—			13,061
Subtotal nuclear decommissioning trust	194,310		351,898		—		592,227			1,138,435
Other special use funds:
Equity securities	37,337		—		—		504		(b)	37,841
U.S. Treasury debt	203,220		—		—		—			203,220
Municipal bonds	—		13,448		—		—			13,448
Subtotal other special use funds	240,557		13,448		—		504			254,509
Total assets	$	434,867	$	374,362	$	4	$	588,460		$	1,397,693
Liabilities
Risk management activities — derivative instruments:
Commodity contracts	$	—	$	(20,498)	$	(1,107)	$	2,986	(a)	$	(18,619)

(a)Represents counterparty netting, margin, and collateral. See Note 7.

(b)Represents net pending securities sales and purchases.

(c)Valued using NAV as a practical expedient and, therefore, are not classified in the fair value hierarchy.