Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2019

Fair Value Disclosures [Abstract]

Schedule of assets and liabilities measured at estimated fair value on a recurring basis

The following table presents information about our gross assets and liabilities that are measured at fair value on a recurring basis as of December 31, 2019 and 2018 (in millions):

	Fair Value Measurements as of December 31, 2019
		Level 1 Inputs		Level 2 Inputs		Level 3 Inputs		Total Fair Value
Assets:
Commodities contracts		$	148.3	$	100.0	$	10.7	$	259.0
Foreign currency contracts		—		2.0		—		2.0
Cash surrender value of life insurance		—		9.4		—		9.4
Total assets at fair value		$	148.3	$	111.4	$	10.7	$	270.4
Liabilities:
Commodities contracts		$	177.6	$	69.3	$	8.1	$	255.0
Foreign currency contracts		—		11.6		—		11.6
Total liabilities at fair value		$	177.6	$	80.9	$	8.1	$	266.6

	Fair Value Measurements as of December 31, 2018
		Level 1 Inputs		Level 2 Inputs		Level 3 Inputs		Total Fair Value
Assets:
Commodities contracts		$	585.6	$	254.6	$	0.9	$	841.2
Foreign currency contracts		—		4.6		—		4.6
Cash surrender value of life insurance		—		6.3		—		6.3
Total assets at fair value		$	585.6	$	265.6	$	0.9	$	852.1
Liabilities:
Commodities contracts		$	556.5	$	211.2	$	0.2	$	767.9
Foreign currency contracts		—		1.2		—		1.2
Total liabilities at fair value		$	556.5	$	212.4	$	0.2	$	769.1

Schedule of commodity derivative assets subject to the right of offset

The following tables summarize those commodity derivative balances subject to the right of offset as presented on our consolidated balance sheet. We have elected to offset the recognized fair value amounts for multiple derivative instruments executed with the same counterparty in our financial statements when a legal right of offset exists.

	Fair Value as of December 31, 2019
		Gross Amounts Recognized		Gross Amounts Offset		Net Amounts Presented		Cash Collateral		Gross Amounts Without Right of Offset		Net Amounts
Assets:
Commodities contracts		$	259.0	$	130.0	$	129.0	$	—	$	—	$	129.0
Foreign currency contracts		2.0		1.0		1.0		—		—		1.0
Total assets at fair value		$	261.1	$	131.1	$	130.0	$	—	$	—	$	130.0
Liabilities:
Commodities contracts		$	255.0	$	130.0	$	125.0	$	29.3	$	—	$	95.7
Foreign currency contracts		11.6		1.0		10.5		—		—		10.5
Total liabilities at fair value		$	266.6	$	131.1	$	135.5	$	29.3	$	—	$	106.3

	Fair Value as of December 31, 2018
		Gross Amounts Recognized		Gross Amounts Offset		Net Amounts Presented		Cash Collateral		Gross Amounts Without Right of Offset		Net Amounts
Assets:
Commodities contracts		$	841.2	$	646.0	$	195.1	$	3.0	$	—	$	192.1
Foreign currency contracts		4.6		0.9		3.7		—		—		3.7
Total assets at fair value		$	845.8	$	647.0	$	198.8	$	3.0	$	—	$	195.8
Liabilities:
Commodities contracts		$	767.9	$	646.0	$	121.9	$	—	$	—	$	121.9
Foreign currency contracts		1.2		0.9		0.3		—		—		0.3
Total liabilities at fair value		$	769.1	$	647.0	$	122.2	$	—	$	—	$	122.2

Schedule of commodity derivative liabilities subject to the right of offset

The following tables summarize those commodity derivative balances subject to the right of offset as presented on our consolidated balance sheet. We have elected to offset the recognized fair value amounts for multiple derivative instruments executed with the same counterparty in our financial statements when a legal right of offset exists.

	Fair Value as of December 31, 2019
		Gross Amounts Recognized		Gross Amounts Offset		Net Amounts Presented		Cash Collateral		Gross Amounts Without Right of Offset		Net Amounts
Assets:
Commodities contracts		$	259.0	$	130.0	$	129.0	$	—	$	—	$	129.0
Foreign currency contracts		2.0		1.0		1.0		—		—		1.0
Total assets at fair value		$	261.1	$	131.1	$	130.0	$	—	$	—	$	130.0
Liabilities:
Commodities contracts		$	255.0	$	130.0	$	125.0	$	29.3	$	—	$	95.7
Foreign currency contracts		11.6		1.0		10.5		—		—		10.5
Total liabilities at fair value		$	266.6	$	131.1	$	135.5	$	29.3	$	—	$	106.3

	Fair Value as of December 31, 2018
		Gross Amounts Recognized		Gross Amounts Offset		Net Amounts Presented		Cash Collateral		Gross Amounts Without Right of Offset		Net Amounts
Assets:
Commodities contracts		$	841.2	$	646.0	$	195.1	$	3.0	$	—	$	192.1
Foreign currency contracts		4.6		0.9		3.7		—		—		3.7
Total assets at fair value		$	845.8	$	647.0	$	198.8	$	3.0	$	—	$	195.8
Liabilities:
Commodities contracts		$	767.9	$	646.0	$	121.9	$	—	$	—	$	121.9
Foreign currency contracts		1.2		0.9		0.3		—		—		0.3
Total liabilities at fair value		$	769.1	$	647.0	$	122.2	$	—	$	—	$	122.2