Consolidated Statement Of Income (Loss) - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating Revenues:
Operating revenues	$ 7,500	$ 7,957	$ 6,394
Operating Expenses:
Fuel	514	473	581
Purchased power	1,298	1,547	606
Natural gas purchased for resale	355	657	442
Other operations and maintenance	1,866	1,937	1,774
Depreciation and amortization	1,387	1,289	1,146
Taxes other than income taxes	522	539	512
Total operating expenses	5,942	6,442	5,061
Operating Income	1,558	1,515	1,333
Other Income, Net	348	226	202
Interest Charges	566	486	383
Income Before Income Taxes	1,340	1,255	1,152
Income Taxes	183	176	157
Net Income	1,157	1,079	995
Less: Net Income Attributable to Noncontrolling Interests	5	5	5
Net Income Attributable to Ameren Common Shareholders	1,152	1,074	990
Pension and other postretirement benefit plan activity, net of income taxes (benefit)	(5)	(14)	14
Comprehensive Income	1,152	1,065	1,009
Less: Comprehensive Income Attributable to Noncontrolling Interests	5	5	5
Comprehensive Income Attributable to Ameren Common Shareholders	$ 1,147	$ 1,060	$ 1,004
Earnings per Common Share – Basic
Earnings per Common Share – Basic	$ 4.39	$ 4.16	$ 3.86
Earnings per Common Share – Diluted
Earnings per Common Share – Diluted	$ 4.38	$ 4.14	$ 3.84
Weighted-average Common Shares Outstanding – Basic	262.8	258.4	256.3
Weighted-average Common Shares Outstanding – Diluted	263.4	259.5	257.6
Ameren Missouri
Operating Revenues:
Operating revenues	$ 3,859	$ 4,046	$ 3,353
Operating Expenses:
Fuel	514	473	581
Purchased power	483	677	227
Natural gas purchased for resale	79	104	60
Other operations and maintenance	1,003	1,028	948
Depreciation and amortization	783	732	632
Taxes other than income taxes	360	363	343
Total operating expenses	3,222	3,377	2,791
Operating Income	637	669	562
Other Income, Net	130	99	99
Interest Charges	227	213	137
Income Before Income Taxes	540	555	524
Income Taxes	(8)	(10)	3
Net Income	548	565	521
Preferred Stock Dividends	3	3	3
Net Income Attributable to Ameren Common Shareholders	545	562	518
Ameren Illinois
Operating Revenues:
Operating revenues	3,482	3,756	2,895
Operating Expenses:
Purchased power	820	880	400
Natural gas purchased for resale	276	553	382
Other operations and maintenance	818	882	820
Depreciation and amortization	556	514	472
Taxes other than income taxes	146	161	153
Total operating expenses	2,616	2,990	2,227
Operating Income	866	766	668
Other Income, Net	156	96	66
Interest Charges	204	168	164
Income Before Income Taxes	818	694	570
Income Taxes	209	179	143
Net Income	609	515	427
Preferred Stock Dividends	2	2	2
Net Income Attributable to Ameren Common Shareholders	607	513	425
Electric
Operating Revenues:
Operating revenues	6,439	6,581	5,297
Electric | Ameren Missouri
Operating Revenues:
Operating revenues	3,694	3,849	3,212
Electric | Ameren Illinois
Operating Revenues:
Operating revenues	2,585	2,576	1,938
Natural gas
Operating Revenues:
Operating revenues	1,061	1,376	1,097
Natural gas | Ameren Missouri
Operating Revenues:
Operating revenues	165	197	141
Natural gas | Ameren Illinois
Operating Revenues:
Operating revenues	$ 897	$ 1,180	$ 957