FAIR VALUE MEASUREMENTS (Tables)

9 Months Ended

Sep. 30, 2020

Fair Value Disclosures [Abstract]

Recurring Fair Value Measurements

The following tables set forth our recurring fair value measurements for the periods indicated:

	September 30, 2020
	Level 1		Level 2		Level 3		Total - Gross		Netting (a)		Total - Net
	(Thousands of dollars)
Derivative assets
Commodity contracts
Financial contracts	$	4,963	$	—	$	41,896	$	46,859	$	(46,859)	$	—
Total derivative assets	$	4,963	$	—	$	41,896	$	46,859	$	(46,859)	$	—
Derivative liabilities
Commodity contracts
Financial contracts	$	(13,509)	$	—	$	(47,240)	$	(60,749)	$	60,749	$	—
Interest-rate contracts	—		(231,991)		—		(231,991)		—		(231,991)
Total derivative liabilities	$	(13,509)	$	(231,991)	$	(47,240)	$	(292,740)	$	60,749	$	(231,991)

(a) - Derivative assets and liabilities are presented in our Consolidated Balance Sheet on a net basis. We net derivative assets and liabilities when a legally enforceable master-netting arrangement exists between the counterparty to a derivative contract and us. At September 30, 2020, we held no cash and posted $48.2 million of cash with various counterparties, including $13.9 million of cash collateral that is offsetting derivative net liability positions under master-netting arrangements in the table above. The remaining $34.3 million of cash collateral in excess of derivative net liability positions is included in other current assets in our Consolidated Balance Sheet.

	December 31, 2019
	Level 1		Level 2		Level 3		Total - Gross		Netting (a)		Total - Net
	(Thousands of dollars)
Derivative assets
Commodity contracts
Financial contracts	$	10,892	$	—	$	55,557	$	66,449	$	(28,588)	$	37,861
Interest-rate contracts	—		581		—		581		—		581
Total derivative assets	$	10,892	$	581	$	55,557	$	67,030	$	(28,588)	$	38,442
Derivative liabilities
Commodity contracts
Financial contracts	$	(4,811)	$	—	$	(24,785)	$	(29,596)	$	28,588	$	(1,008)
Interest-rate contracts	—		(201,941)		—		(201,941)		—		(201,941)
Total derivative liabilities	$	(4,811)	$	(201,941)	$	(24,785)	$	(231,537)	$	28,588	$	(202,949)

(a) - Derivative assets and liabilities are presented in our Consolidated Balance Sheet on a net basis. We net derivative assets and liabilities when a legally enforceable master-netting arrangement exists between the counterparty to a derivative contract and us. At December 31, 2019, we held no cash and posted $8.8 million of cash with various counterparties, which is included in other current assets in our Consolidated Balance Sheet.

Reconciliation of Level 3 Fair Value Measurements

The following table sets forth a reconciliation of our Level 3 fair value measurements for the periods indicated:

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
Derivative Assets (Liabilities)	2020		2019		2020		2019
	(Thousands of dollars)
Net assets at beginning of period	$	5,583	$	19,274	$	30,772	$	40,484
Total changes in fair value:
Settlements included in net income (a)	(6,194)		(12,380)		(29,471)		(38,044)
New Level 3 derivatives included in other comprehensive loss (b)	(2,033)		2,728		(5,140)		17,528
Unrealized change included in other comprehensive loss (b)	(2,700)		18,593		(1,505)		8,247
Net assets (liabilities) at end of period	$	(5,344)	$	28,215	$	(5,344)	$	28,215

(a) - Included in commodity sales revenues/cost of sales and fuel in our Consolidated Statements of Income.

(b) - Included in change in fair value of derivatives in our Consolidated Statements of Comprehensive Income.