Consolidated Statements Of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flows from (used for) operating activities:
Net income	$ 674	$ 624	$ 567
Adjustments to reconcile net income to net cash flows from (used for) operating activities:
Depreciation and amortization	657	615	567
Deferred tax expense (benefit) and tax credits	(78)	(66)	56
Equity component of allowance for funds used during construction	(18)	(39)	(66)
Other	35	37	20
Other changes in assets and liabilities:
Accounts receivable	(530)	(468)	(472)
Derivative assets	(142)	(7)	2
Regulatory assets	51	(130)	(16)
Regulatory liabilities	(66)	(113)	(40)
Deferred income taxes	193	171	54
Pension and other benefit obligations	(137)	27	(25)
DAEC PPA amendment buyout payment	0	(110)	0
Other	(57)	(40)	13
Net cash flows from (used for) operating activities	582	501	660
Cash flows from (used for) investing activities:
Utility construction and acquisition expenditures	(1,070)	(1,293)	(1,539)
Other construction and acquisition expenditures	(99)	(73)	(101)
Cash receipts on sold receivables	502	458	413
Other	(61)	(43)	(60)
Net cash flows from (used for) investing activities	(728)	(951)	(1,287)
Cash flows from financing activities:
Common stock dividends	(403)	(377)	(337)
Proceeds from issuance of common stock, net	28	247	390
Payments to redeem cumulative preferred stock of IPL	(200)	0	0
Proceeds from issuance of long-term debt	600	1,250	950
Payments to retire long-term debt	(8)	(657)	(256)
Net change in commercial paper	126	52	(104)
Other	(13)	(27)	(24)
Net cash flows from (used for) financing activities	130	488	619
Net increase (decrease) in cash, cash equivalents and restricted cash	(16)	38	(8)
Cash, cash equivalents and restricted cash at beginning of period	56	18	26
Cash, cash equivalents and restricted cash at end of period	40	56	18
Supplemental cash flows information:
Interest	(272)	(274)	(268)
Income taxes, net	(3)	5	21
Significant non-cash investing and financing activities:
Accrued capital expenditures	141	131	196
Beneficial interest obtained in exchange for securitized accounts receivable	214	188	188
IPL [Member]
Cash flows from (used for) operating activities:
Net income	365	334	294
Adjustments to reconcile net income to net cash flows from (used for) operating activities:
Depreciation and amortization	375	356	327
Deferred tax expense (benefit) and tax credits	(14)	(52)	15
Equity component of allowance for funds used during construction	(7)	(17)	(35)
Other	11	12	1
Other changes in assets and liabilities:
Accounts receivable	(539)	(466)	(467)
Derivative assets	(55)	(7)	(5)
Regulatory assets	30	(93)	(11)
Accounts payable	15	6	(21)
Regulatory liabilities	1	(20)	2
Deferred income taxes	62	79	35
Pension and other benefit obligations	(59)	18	(11)
DAEC PPA amendment buyout payment	0	(110)	0
Other	(32)	(46)	49
Net cash flows from (used for) operating activities	153	(6)	173
Cash flows from (used for) investing activities:
Utility construction and acquisition expenditures	(384)	(687)	(1,020)
Cash receipts on sold receivables	502	458	413
Other	(27)	(72)	(60)
Net cash flows from (used for) investing activities	91	(301)	(667)
Cash flows from financing activities:
Common stock dividends	(400)	(236)	(168)
Capital contributions from parent	50	404	125
Payments to redeem cumulative preferred stock of IPL	(200)	0	0
Proceeds from issuance of long-term debt	300	400	600
Payments to retire long-term debt	0	(200)	0
Net change in commercial paper	0	0	(50)
Other	(10)	(20)	(16)
Net cash flows from (used for) financing activities	(260)	348	491
Net increase (decrease) in cash, cash equivalents and restricted cash	(16)	41	(3)
Cash, cash equivalents and restricted cash at beginning of period	50	9	12
Cash, cash equivalents and restricted cash at end of period	34	50	9
Supplemental cash flows information:
Interest	(138)	(141)	(122)
Income taxes, net	47	(18)	7
Significant non-cash investing and financing activities:
Accrued capital expenditures	57	73	112
Beneficial interest obtained in exchange for securitized accounts receivable	214	188	188
WPL [Member]
Cash flows from (used for) operating activities:
Net income	268	249	233
Adjustments to reconcile net income to net cash flows from (used for) operating activities:
Depreciation and amortization	276	254	236
Deferred tax expense (benefit) and tax credits	(79)	(15)	24
Other	11	2	(12)
Other changes in assets and liabilities:
Derivative assets	(87)	0	6
Regulatory liabilities	(67)	(93)	(42)
Deferred income taxes	132	90	20
Pension and other benefit obligations	(63)	11	(7)
Other	(20)	(32)	(35)
Net cash flows from (used for) operating activities	371	466	423
Cash flows from (used for) investing activities:
Utility construction and acquisition expenditures	(686)	(606)	(519)
Other	(30)	(7)	(38)
Net cash flows from (used for) investing activities	(716)	(613)	(557)
Cash flows from financing activities:
Common stock dividends	(168)	(160)	(144)
Capital contributions from parent	245	25	125
Proceeds from issuance of long-term debt	300	350	350
Payments to retire long-term debt	0	(150)	(250)
Net change in commercial paper	(21)	89	63
Other	(12)	(8)	(15)
Net cash flows from (used for) financing activities	344	146	129
Net increase (decrease) in cash, cash equivalents and restricted cash	(1)	(1)	(5)
Cash, cash equivalents and restricted cash at beginning of period	3	4	9
Cash, cash equivalents and restricted cash at end of period	2	3	4
Supplemental cash flows information:
Interest	(101)	(102)	(103)
Income taxes, net	(38)	13	(29)
Significant non-cash investing and financing activities:
Accrued capital expenditures	$ 81	$ 55	$ 82