Derivatives and Risk Management Activities - Commodity Price Risk Hedging (Details) bbl in Millions	3 Months Ended
	Mar. 31, 2020 TWh MMBbls Bcf bbl
Net long position associated with crude oil purchases
Commodity Price Risk Hedging:
Derivative position notional amount (in barrels, MMbls or Bcf)	9.9
Net short time spread position hedging anticipated crude oil lease gathering purchases
Commodity Price Risk Hedging:
Derivative position notional amount (in barrels, MMbls or Bcf)	6.0
Net crude oil basis spread position
Commodity Price Risk Hedging:
Derivative position notional amount (in barrels, MMbls or Bcf)	6.3
Net short position related to anticipated net sales of crude oil and NGL inventory
Commodity Price Risk Hedging:
Derivative position notional amount (in barrels, MMbls or Bcf)	15.7
Positions hedging risk storage capacity will not be utilized
Commodity Price Risk Hedging:
Derivative position notional amount (in barrels, MMbls or Bcf)	2.0
Long natural gas position for natural gas purchases and operational needs
Commodity Price Risk Hedging:
Derivative position notional amount (in barrels, MMbls or Bcf) | Bcf	41.8
Short propane position related to subsequent sale of products
Commodity Price Risk Hedging:
Derivative position notional amount (in barrels, MMbls or Bcf) | MMBbls	3.0
Short butane position related to subsequent sale of products
Commodity Price Risk Hedging:
Derivative position notional amount (in barrels, MMbls or Bcf) | MMBbls	1.8
Short condensate WTI position related to subsequent sale of products
Commodity Price Risk Hedging:
Derivative position notional amount (in barrels, MMbls or Bcf) | MMBbls	0.9
Long power position for power supply requirements
Commodity Price Risk Hedging:
Derivative position notional amount (in Terawatt hours) | TWh	0.9