Debt Instrument, Unamortized Discount or Premium and Debt Issuance Costs

No definition available.

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- Definition

Face (par) amount of debt instrument at time of issuance.

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

Amount, after deduction of unamortized premium (discount) and debt issuance cost, of long-term debt. Excludes lease obligation.

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing after fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Balance Type:
Period Type:

Long-Term Debt And Equity Financings (Schedule Of Maturities Of Long-Term Debt) (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024	Aug. 31, 2024
Debt Instrument [Line Items]
2026	$ 973
2027	974
2028	966
2029	1,207
2030	917
Thereafter	14,394
Total	19,431
Ameren (parent)
Debt Instrument [Line Items]
2026	950
2027	500
2028	450
2029	700
2030	0
Thereafter	1,550
Total	4,150
Unamortized discount, premium, and debt issuance costs	19
Ameren Missouri
Debt Instrument [Line Items]
2026	23
2027	424
2028	26
2029	477
2030	493
Thereafter	6,864
Total	8,307
Unamortized discount, premium, and debt issuance costs	77
Ameren Illinois
Debt Instrument [Line Items]
2026	0
2027	0
2028	490
2029	0
2030	375
Thereafter	5,448
Total	6,313
Unamortized discount, premium, and debt issuance costs	54
Ameren Transmission Company of Illinois
Debt Instrument [Line Items]
2026	0
2027	50
2028	0
2029	30
2030	49
Thereafter	532
Total	661
Unamortized discount, premium, and debt issuance costs	2
Unsecured Debt \| Ameren Transmission Company of Illinois \| 2.45% Senior unsecured notes due 2036
Debt Instrument [Line Items]
Debt instrument face amount	$ 75	$ 75
Long-term debt interest rate	2.45%
Unsecured Debt \| Ameren Transmission Company of Illinois \| 2.45% Senior unsecured notes due 2036 \| Debt Instrument, Redemption, Period One
Debt Instrument [Line Items]
Thereafter	$ 30
Unsecured Debt \| Ameren Transmission Company of Illinois \| 2.45% Senior unsecured notes due 2036 \| Debt Instrument, Redemption, Period Two
Debt Instrument [Line Items]
Thereafter	45
Unsecured Debt \| Ameren Transmission Company of Illinois \| 3.43% Senior unsecured notes due 2050
Debt Instrument [Line Items]
Debt instrument face amount	$ 351	351
Long-term debt interest rate	3.43%		3.43%
Unsecured Debt \| Ameren Transmission Company of Illinois \| 3.43% Senior unsecured notes due 2050 \| Debt Instrument, Redemption, Period Three
Debt Instrument [Line Items]
Thereafter	$ 50
Unsecured Debt \| Ameren Transmission Company of Illinois \| 3.43% Senior unsecured notes due 2050 \| Debt Instrument, Redemption, Period Four
Debt Instrument [Line Items]
Thereafter	49
Unsecured Debt \| Ameren Transmission Company of Illinois \| 3.43% Senior unsecured notes due 2050 \| Debt Instrument, Redemption, Period Five
Debt Instrument [Line Items]
Thereafter	50
Unsecured Debt \| Ameren Transmission Company of Illinois \| 3.43% Senior unsecured notes due 2050 \| Debt Instrument, Redemption, Period Six
Debt Instrument [Line Items]
Thereafter	49
Unsecured Debt \| Ameren Transmission Company of Illinois \| 3.43% Senior unsecured notes due 2050 \| Debt Instrument, Redemption, Period Seven
Debt Instrument [Line Items]
Thereafter	77
Unsecured Debt \| Ameren Transmission Company of Illinois \| 3.43% Senior unsecured notes due 2050 \| Debt Instrument, Redemption, Period Eight
Debt Instrument [Line Items]
Thereafter	76
Unsecured Debt \| Ameren Transmission Company of Illinois \| 2.96% Senior unsecured notes due 2052
Debt Instrument [Line Items]
Debt instrument face amount	$ 95	$ 95
Long-term debt interest rate	2.96%
Unsecured Debt \| Ameren Transmission Company of Illinois \| 2.96% Senior unsecured notes due 2052 \| Debt Instrument, Redemption, Period One
Debt Instrument [Line Items]
Thereafter	$ 45
Unsecured Debt \| Ameren Transmission Company of Illinois \| 2.96% Senior unsecured notes due 2052 \| Debt Instrument, Redemption, Period Two
Debt Instrument [Line Items]
Thereafter	$ 50