Consolidated Statements of Equity (Unaudited) (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018
Balance, end of period	$ 8,392		$ 7,943	$ 8,337
COMMON STOCK
Balance, end of period	$ 561	$ 561	$ 561	$ 561	$ 561	$ 561