Fair Value Measurements - Additional Information (Details) MMBTU in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) Contract counterparty MMBbls	Dec. 31, 2018 USD ($) MMBTU MMBbls
Derivative [Line Items]
Gain on derivative instruments | $	$ (81)	$ 84
Number of counterparties | counterparty	2
Derivatives not designated as accounting hedges | Oil derivatives
Derivative [Line Items]
Volume notional amount (in MMBbls) | MMBbls	14	16
Derivatives not designated as accounting hedges | Natural gas derivatives
Derivative [Line Items]
Energy notional amount (in MMBtu) | MMBTU		26
Designated as accounting hedges
Derivative [Line Items]
Number of derivative contracts designated as accounting hedges | Contract	0