Statements of Cash Flows - MPC (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Net cash paid for capitalized interest	$ 92	$ 81	$ 74
Mississippi Power
Net cash paid for capitalized interest	$ 0	$ 0	$ 1