Schedule I - Condensed Financial Information - Balance Sheet (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Current Assets
Cash and temporary cash investments	$ 992	$ 1,272
Accounts receivable - customers, less allowance for uncollectible accounts	1,943	1,701
Taxes receivable	13	26
Prepayments	295	271
Other current assets	361	231
TOTAL CURRENT ASSETS	5,551	5,301
Investments in subsidiaries and others	853	1,816
Goodwill	439	446
Other noncurrent assets	8,116	9,223
TOTAL ASSETS	63,116	62,895	$ 58,079
Current Liabilities
Long-term debt due within one year		1,967
Term Loan	0	165
Notes payable	1,488	1,705
Accounts payable	1,497	1,475
Accrued taxes	104	150
Other current liabilities	461	426
TOTAL CURRENT LIABILITIES	5,427	7,354
Long-term debt	22,604	20,382
Shareholders’ Equity
Equity	20,037	18,847
TOTAL LIABILITIES AND EQUITY	63,116	62,895
Parent Company
Current Assets
Cash and temporary cash investments	19	144
Accounts receivable - customers, less allowance for uncollectible accounts	0	1
Taxes receivable	3	18
Accounts receivable from affiliated companies	1,199	1,256
Prepayments	28	62
Other current assets	14	12
TOTAL CURRENT ASSETS	1,263	1,493
Investments in subsidiaries and others	19,951	18,670
Goodwill	406	406
Deferred income tax	0	55
Long-term debt receivable from affiliated companies	0	875
TOTAL ASSETS	21,620	21,499
Current Liabilities
Long-term debt due within one year	293	1,178
Notes payable	50	0
Accounts payable	1	0
Accounts payable to affiliated companies	517	517
Accrued taxes	2	6
Other current liabilities	9	12
TOTAL CURRENT LIABILITIES	872	1,713
Deferred income tax	64	0
Total Liabilities	936	1,713
Long-term debt	647	939
Shareholders’ Equity
Common stock, including additional paid-in capital	9,748	8,844
Retained earnings	10,289	10,003
Equity	20,037	18,847
TOTAL LIABILITIES AND EQUITY	$ 21,620	$ 21,499