Consolidated Balance Sheets - PAC (Parenthetical) - $ / shares shares in Millions	Dec. 31, 2021	Dec. 31, 2020
Common stock, shares authorized	115	115
Common stock, no par value (in dollars per share)	$ 0	$ 0
Common stock, shares issued	76	76
Common stock, shares outstanding	76	76
PAC
Common stock, shares authorized	750	750
Common stock, no par value (in dollars per share)	$ 0	$ 0
Common stock, shares issued	357	357
Common stock, shares outstanding	357	357