Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Oil and natural gas properties, amortization excluded	$ 9,207	$ 9,670
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Shares authorized (in Shares)	200,000,000	200,000,000
Shares issued (in Shares)	159,002,338	164,273,447
Shares outstanding (in Shares)	159,002,338	164,273,447

The sum of the capitalized costs incurred, as of the balance sheet date, of unproved properties excluded from amortization including acquisition costs, exploration costs, development costs, and production costs.

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