Commitments and Contingencies - Legal, Environmental or Regulatory (Details) $ in Thousands	1 Months Ended	12 Months Ended	68 Months Ended
	May 31, 2015 bbl	Dec. 31, 2020 USD ($)	Dec. 31, 2020 USD ($) lawsuit	Dec. 31, 2019 USD ($)	Apr. 25, 2019 USD ($)	Sep. 07, 2018 count
Legal, Environmental or Regulatory Matters
Estimated undiscounted reserve for environmental liabilities		$ 141,000	$ 141,000	$ 140,000
Estimated undiscounted reserve for environmental liabilities, short-term		94,000	94,000	60,000
Amounts probable of recovery under insurance and from third parties under indemnification agreements		97,000	97,000	72,000
Other long-term liabilities and deferred credits
Legal, Environmental or Regulatory Matters
Estimated undiscounted reserve for environmental liabilities, long-term		47,000	47,000	80,000
Trade accounts receivable and other receivables, net
Legal, Environmental or Regulatory Matters
Amounts probable of recovery under insurance and from third parties under indemnification agreements		96,000	96,000	35,000
Other long-term assets, net
Legal, Environmental or Regulatory Matters
Amounts probable of recovery under insurance and from third parties under indemnification agreements		1,000	1,000	$ 37,000
Line 901 Incident
Legal, Environmental or Regulatory Matters
Estimated undiscounted reserve for environmental liabilities		86,000	86,000
Amounts probable of recovery under insurance and from third parties under indemnification agreements		90,000	90,000
Estimated size of release (in bbl) | bbl	2,934
Estimated size of release to reach Pacific Ocean (in bbl) | bbl	598
Aggregate total estimated costs		460,000	460,000
Recoveries from insurance carriers			245,000
Total release costs probable of recovery		335,000	$ 335,000
Line 901 Incident | Civil Penalties
Legal, Environmental or Regulatory Matters
Penalties or compensation paid		24,000
Line 901 Incident | Compensation for Injuries to, Destruction of, Loss of Use of, Natural Resources
Legal, Environmental or Regulatory Matters
Penalties or compensation paid		$ 22,325
Line 901 Incident | May 2016 Indictment
Legal, Environmental or Regulatory Matters
Number of felony charges found guilty | count						1
Number of misdemeanor charges found guilty | count						8
Number of misdemeanor charges found guilty, reporting | count						1
Number of misdemeanor charges found guilty, strict liability discharge | count						1
Number of misdemeanor charges found guilty, strict liability animal takings | count						6
Fines or penalties assessed					$ 3,350
Number of misdemeanor charges not guilty, strict liability animal takings | count						1
Line 901 Incident | Class Action Lawsuits
Legal, Environmental or Regulatory Matters
Number of cases filed during the period | lawsuit			9
Line 901 Incident | Unitholder Derivative Lawsuits
Legal, Environmental or Regulatory Matters
Number of cases filed during the period | lawsuit			4