Acquisitions (Details) a in Thousands, $ in Millions	1 Months Ended	9 Months Ended
	Nov. 07, 2019 USD ($) a	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)
Subsequent Event [Line Items]
Payments to Acquire Businesses, Net of Cash Acquired		$ 0	$ 25
TexasDelaware | Subsequent Event
Subsequent Event [Line Items]
Oil and Gas Acres Undeveloped and Developed, Net | a	40
Payments to Acquire Businesses, Net of Cash Acquired	$ 106
Eagle Ford | Subsequent Event
Subsequent Event [Line Items]
Oil and Gas Acres Undeveloped and Developed, Net | a	18
Payments to Acquire Businesses, Net of Cash Acquired	$ 185