Fair Value Long-term Debt, Other Temporary Investments, Nuclear Trusts (Details) - USD ($)
|
3 Months Ended |
6 Months Ended |
12 Months Ended |
Jun. 30, 2024 |
Jun. 30, 2023 |
Jun. 30, 2024 |
Jun. 30, 2023 |
Dec. 31, 2023 |
Book Values and Fair Values of Long - term Debt |
|
|
|
|
|
|
|
|
Total Long-term Debt Outstanding |
|
$ 42,062,300,000
|
|
|
$ 42,062,300,000
|
|
|
$ 40,143,200,000
|
Long Term Debt, Fair Value |
|
37,897,100,000
|
|
|
37,897,100,000
|
|
|
37,325,700,000
|
Other Temporary Investments |
|
|
|
|
|
|
|
|
Cost |
|
248,400,000
|
|
|
248,400,000
|
|
|
243,500,000
|
Gross Unrealized Gains |
|
29,900,000
|
|
|
29,900,000
|
|
|
25,900,000
|
Gross Unrealized Losses |
|
(7,200,000)
|
|
|
(7,200,000)
|
|
|
(6,200,000)
|
Other Short-term Investments |
|
271,100,000
|
|
|
271,100,000
|
|
|
263,200,000
|
Debt and Equity Securities Within Other Temporary Investments |
|
|
|
|
|
|
|
|
Proceeds from Investment Sales |
|
0
|
|
$ 0
|
3,000,000.0
|
|
$ 0
|
|
Purchases of Investments |
|
1,500,000
|
|
1,300,000
|
3,000,000.0
|
|
2,300,000
|
|
Gross Realized Gains on Investment Sales |
|
0
|
|
0
|
300,000
|
|
0
|
|
Gross Realized Losses on Investment Sales |
|
0
|
|
0
|
200,000
|
|
0
|
|
Nuclear Trust Fund Investments |
|
|
|
|
|
|
|
|
Fair Value |
|
4,214,000,000
|
|
|
4,214,000,000
|
|
|
3,860,200,000
|
Securities Activity Within Decommissioning and SNF Trusts |
|
|
|
|
|
|
|
|
Payments to Acquire Investments |
|
|
|
|
1,190,100,000
|
|
1,235,600,000
|
|
Contractual Maturities, Fair Value of Debt Securities |
|
|
|
|
|
|
|
|
Fair Value |
|
4,214,000,000
|
|
|
4,214,000,000
|
|
|
3,860,200,000
|
Other [Member] |
|
|
|
|
|
|
|
|
Other Temporary Investments |
|
|
|
|
|
|
|
|
Other Short-term Investments |
|
21,900,000
|
|
|
21,900,000
|
|
|
13,900,000
|
Nuclear Trust Fund Investments |
|
|
|
|
|
|
|
|
Fair Value |
|
12,600,000
|
|
|
12,600,000
|
|
|
9,000,000.0
|
Contractual Maturities, Fair Value of Debt Securities |
|
|
|
|
|
|
|
|
Fair Value |
|
12,600,000
|
|
|
12,600,000
|
|
|
9,000,000.0
|
Spent Nuclear Fuel and Decommissioning Trusts [Member] |
|
|
|
|
|
|
|
|
Securities Activity Within Decommissioning and SNF Trusts |
|
|
|
|
|
|
|
|
Payments to Acquire Investments |
|
598,600,000
|
|
697,000,000.0
|
1,187,100,000
|
|
1,233,300,000
|
|
Contractual Maturities, Fair Value of Debt Securities |
|
|
|
|
|
|
|
|
Within 1 year |
|
340,200,000
|
|
|
340,200,000
|
|
|
|
After 1 year through 5 years |
|
574,200,000
|
|
|
574,200,000
|
|
|
|
After 5 years through 10 years |
|
213,200,000
|
|
|
213,200,000
|
|
|
|
After 10 years |
|
264,900,000
|
|
|
264,900,000
|
|
|
|
Fair Value Measurements (Textuals) |
|
|
|
|
|
|
|
|
Adjusted Cost of Debt Securities |
|
1,400,000,000
|
|
|
1,400,000,000
|
|
|
1,400,000,000
|
Adjusted Cost of Domestic Equity Securities |
|
587,000,000
|
|
|
587,000,000
|
|
|
568,000,000
|
Other than Temporary Impairment Losses, Investments |
|
|
|
|
(27,400,000)
|
|
|
(41,800,000)
|
Proceeds from Sale of Other Investments |
|
584,600,000
|
|
688,700,000
|
1,154,100,000
|
|
1,206,300,000
|
|
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax |
|
(12,400,000)
|
|
|
(12,400,000)
|
|
|
(10,000,000.0)
|
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax |
|
2,229,100,000
|
|
|
2,229,100,000
|
|
|
1,902,900,000
|
Spent Nuclear Fuel and Decommissioning Trusts [Member] | Gain [Member] |
|
|
|
|
|
|
|
|
Securities Activity Within Decommissioning and SNF Trusts |
|
|
|
|
|
|
|
|
Realized Investment Gains (Losses) |
|
4,900,000
|
|
6,400,000
|
10,300,000
|
|
54,800,000
|
|
Spent Nuclear Fuel and Decommissioning Trusts [Member] | Loss [Member] |
|
|
|
|
|
|
|
|
Securities Activity Within Decommissioning and SNF Trusts |
|
|
|
|
|
|
|
|
Gain (Loss) on Investments |
|
4,200,000
|
|
3,700,000
|
5,400,000
|
|
12,300,000
|
|
Cash [Member] |
|
|
|
|
|
|
|
|
Other Temporary Investments |
|
|
|
|
|
|
|
|
Cost |
[1] |
45,400,000
|
|
|
45,400,000
|
|
|
48,900,000
|
Gross Unrealized Gains |
[1] |
0
|
|
|
0
|
|
|
0
|
Gross Unrealized Losses |
[1] |
0
|
|
|
0
|
|
|
0
|
Other Short-term Investments |
[1] |
45,400,000
|
|
|
45,400,000
|
|
|
48,900,000
|
Fixed Income Funds [Member] |
|
|
|
|
|
|
|
|
Nuclear Trust Fund Investments |
|
|
|
|
|
|
|
|
Fair Value |
|
1,392,500,000
|
|
|
1,392,500,000
|
|
|
1,406,800,000
|
Contractual Maturities, Fair Value of Debt Securities |
|
|
|
|
|
|
|
|
Fair Value |
|
1,392,500,000
|
|
|
1,392,500,000
|
|
|
1,406,800,000
|
Fixed Income Funds [Member] | Other [Member] |
|
|
|
|
|
|
|
|
Nuclear Trust Fund Investments |
|
|
|
|
|
|
|
|
Fair Value |
|
0
|
|
|
0
|
|
|
0
|
Contractual Maturities, Fair Value of Debt Securities |
|
|
|
|
|
|
|
|
Fair Value |
|
0
|
|
|
0
|
|
|
0
|
Fixed Income Funds [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member] |
|
|
|
|
|
|
|
|
Fair Value Measurements (Textuals) |
|
|
|
|
|
|
|
|
Other than Temporary Impairment Losses, Investments |
|
|
|
|
(27,400,000)
|
|
|
(41,800,000)
|
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax |
|
(10,600,000)
|
|
|
(10,600,000)
|
|
|
(9,100,000)
|
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax |
|
15,100,000
|
|
|
15,100,000
|
|
|
33,400,000
|
Mutual Funds Fixed Income [Member] |
|
|
|
|
|
|
|
|
Other Temporary Investments |
|
|
|
|
|
|
|
|
Cost |
[2] |
166,200,000
|
|
|
166,200,000
|
|
|
165,900,000
|
Gross Unrealized Gains |
[2] |
0
|
|
|
0
|
|
|
0
|
Gross Unrealized Losses |
[2] |
(7,200,000)
|
|
|
(7,200,000)
|
|
|
(6,200,000)
|
Other Short-term Investments |
[2] |
159,000,000.0
|
|
|
159,000,000.0
|
|
|
159,700,000
|
Mutual Funds Fixed Income [Member] | Other [Member] |
|
|
|
|
|
|
|
|
Other Temporary Investments |
|
|
|
|
|
|
|
|
Other Short-term Investments |
|
0
|
|
|
0
|
|
|
0
|
Domestic [Member] |
|
|
|
|
|
|
|
|
Nuclear Trust Fund Investments |
|
|
|
|
|
|
|
|
Fair Value |
[3] |
2,798,700,000
|
|
|
2,798,700,000
|
|
|
2,436,600,000
|
Contractual Maturities, Fair Value of Debt Securities |
|
|
|
|
|
|
|
|
Fair Value |
[3] |
2,798,700,000
|
|
|
2,798,700,000
|
|
|
2,436,600,000
|
Domestic [Member] | Other [Member] |
|
|
|
|
|
|
|
|
Nuclear Trust Fund Investments |
|
|
|
|
|
|
|
|
Fair Value |
[3] |
0
|
|
|
0
|
|
|
0
|
Contractual Maturities, Fair Value of Debt Securities |
|
|
|
|
|
|
|
|
Fair Value |
[3] |
0
|
|
|
0
|
|
|
0
|
Domestic [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member] |
|
|
|
|
|
|
|
|
Fair Value Measurements (Textuals) |
|
|
|
|
|
|
|
|
Other than Temporary Impairment Losses, Investments |
|
|
|
|
0
|
|
|
0
|
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax |
|
(1,800,000)
|
|
|
(1,800,000)
|
|
|
(900,000)
|
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax |
|
2,214,000,000
|
|
|
2,214,000,000
|
|
|
1,869,500,000
|
Mutual Funds Equity [Member] |
|
|
|
|
|
|
|
|
Other Temporary Investments |
|
|
|
|
|
|
|
|
Cost |
|
14,900,000
|
|
|
14,900,000
|
|
|
14,800,000
|
Gross Unrealized Gains |
|
29,900,000
|
|
|
29,900,000
|
|
|
25,900,000
|
Gross Unrealized Losses |
|
0
|
|
|
0
|
|
|
0
|
Other Short-term Investments |
[3] |
44,800,000
|
|
|
44,800,000
|
|
|
40,700,000
|
Mutual Funds Equity [Member] | Other [Member] |
|
|
|
|
|
|
|
|
Other Temporary Investments |
|
|
|
|
|
|
|
|
Other Short-term Investments |
[3] |
0
|
|
|
0
|
|
|
0
|
Cash and Cash Equivalents [Member] |
|
|
|
|
|
|
|
|
Nuclear Trust Fund Investments |
|
|
|
|
|
|
|
|
Fair Value |
[4] |
22,800,000
|
|
|
22,800,000
|
|
|
16,800,000
|
Contractual Maturities, Fair Value of Debt Securities |
|
|
|
|
|
|
|
|
Fair Value |
[4] |
22,800,000
|
|
|
22,800,000
|
|
|
16,800,000
|
Cash and Cash Equivalents [Member] | Other [Member] |
|
|
|
|
|
|
|
|
Nuclear Trust Fund Investments |
|
|
|
|
|
|
|
|
Fair Value |
[4] |
12,600,000
|
|
|
12,600,000
|
|
|
9,000,000.0
|
Contractual Maturities, Fair Value of Debt Securities |
|
|
|
|
|
|
|
|
Fair Value |
[4] |
12,600,000
|
|
|
12,600,000
|
|
|
9,000,000.0
|
Cash and Cash Equivalents [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member] |
|
|
|
|
|
|
|
|
Fair Value Measurements (Textuals) |
|
|
|
|
|
|
|
|
Other than Temporary Impairment Losses, Investments |
|
|
|
|
0
|
|
|
0
|
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax |
|
0
|
|
|
0
|
|
|
0
|
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax |
|
0
|
|
|
0
|
|
|
0
|
US Government Agencies Debt Securities [Member] |
|
|
|
|
|
|
|
|
Nuclear Trust Fund Investments |
|
|
|
|
|
|
|
|
Fair Value |
|
1,267,800,000
|
|
|
1,267,800,000
|
|
|
1,273,000,000
|
Contractual Maturities, Fair Value of Debt Securities |
|
|
|
|
|
|
|
|
Fair Value |
|
1,267,800,000
|
|
|
1,267,800,000
|
|
|
1,273,000,000
|
US Government Agencies Debt Securities [Member] | Other [Member] |
|
|
|
|
|
|
|
|
Nuclear Trust Fund Investments |
|
|
|
|
|
|
|
|
Fair Value |
|
0
|
|
|
0
|
|
|
0
|
Contractual Maturities, Fair Value of Debt Securities |
|
|
|
|
|
|
|
|
Fair Value |
|
0
|
|
|
0
|
|
|
0
|
US Government Agencies Debt Securities [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member] |
|
|
|
|
|
|
|
|
Fair Value Measurements (Textuals) |
|
|
|
|
|
|
|
|
Other than Temporary Impairment Losses, Investments |
|
|
|
|
(26,600,000)
|
|
|
(33,200,000)
|
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax |
|
(3,600,000)
|
|
|
(3,600,000)
|
|
|
(3,900,000)
|
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax |
|
13,800,000
|
|
|
13,800,000
|
|
|
28,600,000
|
Corporate Debt [Member] |
|
|
|
|
|
|
|
|
Nuclear Trust Fund Investments |
|
|
|
|
|
|
|
|
Fair Value |
|
123,000,000.0
|
|
|
123,000,000.0
|
|
|
132,100,000
|
Contractual Maturities, Fair Value of Debt Securities |
|
|
|
|
|
|
|
|
Fair Value |
|
123,000,000.0
|
|
|
123,000,000.0
|
|
|
132,100,000
|
Corporate Debt [Member] | Other [Member] |
|
|
|
|
|
|
|
|
Nuclear Trust Fund Investments |
|
|
|
|
|
|
|
|
Fair Value |
|
0
|
|
|
0
|
|
|
0
|
Contractual Maturities, Fair Value of Debt Securities |
|
|
|
|
|
|
|
|
Fair Value |
|
0
|
|
|
0
|
|
|
0
|
Corporate Debt [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member] |
|
|
|
|
|
|
|
|
Fair Value Measurements (Textuals) |
|
|
|
|
|
|
|
|
Other than Temporary Impairment Losses, Investments |
|
|
|
|
(800,000)
|
|
|
(8,600,000)
|
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax |
|
(7,000,000.0)
|
|
|
(7,000,000.0)
|
|
|
(5,200,000)
|
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax |
|
1,300,000
|
|
|
1,300,000
|
|
|
4,800,000
|
State and Local Jurisdiction [Member] |
|
|
|
|
|
|
|
|
Nuclear Trust Fund Investments |
|
|
|
|
|
|
|
|
Fair Value |
|
1,700,000
|
|
|
1,700,000
|
|
|
1,700,000
|
Contractual Maturities, Fair Value of Debt Securities |
|
|
|
|
|
|
|
|
Fair Value |
|
1,700,000
|
|
|
1,700,000
|
|
|
1,700,000
|
State and Local Jurisdiction [Member] | Other [Member] |
|
|
|
|
|
|
|
|
Nuclear Trust Fund Investments |
|
|
|
|
|
|
|
|
Fair Value |
|
0
|
|
|
0
|
|
|
0
|
Contractual Maturities, Fair Value of Debt Securities |
|
|
|
|
|
|
|
|
Fair Value |
|
0
|
|
|
0
|
|
|
0
|
State and Local Jurisdiction [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member] |
|
|
|
|
|
|
|
|
Fair Value Measurements (Textuals) |
|
|
|
|
|
|
|
|
Other than Temporary Impairment Losses, Investments |
|
|
|
|
0
|
|
|
0
|
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax |
|
0
|
|
|
0
|
|
|
0
|
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax |
|
0
|
|
|
0
|
|
|
0
|
Other Cash Deposits [Member] |
|
|
|
|
|
|
|
|
Other Temporary Investments |
|
|
|
|
|
|
|
|
Cost |
|
21,900,000
|
[5] |
|
21,900,000
|
[5] |
|
13,900,000
|
Gross Unrealized Gains |
|
0
|
|
|
0
|
|
|
0
|
Gross Unrealized Losses |
|
0
|
|
|
0
|
|
|
0
|
Other Short-term Investments |
|
21,900,000
|
[5] |
|
21,900,000
|
[5] |
|
13,900,000
|
Other Cash Deposits [Member] | Other [Member] |
|
|
|
|
|
|
|
|
Other Temporary Investments |
|
|
|
|
|
|
|
|
Other Short-term Investments |
[7] |
21,900,000
|
[6] |
|
21,900,000
|
[6] |
|
13,900,000
|
Other Cash Deposits [Member] | AEP OnSite Partners |
|
|
|
|
|
|
|
|
Other Temporary Investments |
|
|
|
|
|
|
|
|
Other Short-term Investments |
|
300,000
|
|
|
300,000
|
|
|
|
AEP Texas Inc. [Member] |
|
|
|
|
|
|
|
|
Book Values and Fair Values of Long - term Debt |
|
|
|
|
|
|
|
|
Total Long-term Debt Outstanding |
|
6,489,700,000
|
|
|
6,489,700,000
|
|
|
5,889,800,000
|
Long Term Debt, Fair Value |
|
5,779,100,000
|
|
|
5,779,100,000
|
|
|
5,400,700,000
|
AEP Transmission Co [Member] |
|
|
|
|
|
|
|
|
Book Values and Fair Values of Long - term Debt |
|
|
|
|
|
|
|
|
Total Long-term Debt Outstanding |
|
5,861,500,000
|
|
|
5,861,500,000
|
|
|
5,414,400,000
|
Long Term Debt, Fair Value |
|
4,867,600,000
|
|
|
4,867,600,000
|
|
|
4,796,900,000
|
Appalachian Power Co [Member] |
|
|
|
|
|
|
|
|
Book Values and Fair Values of Long - term Debt |
|
|
|
|
|
|
|
|
Total Long-term Debt Outstanding |
|
5,672,000,000
|
|
|
5,672,000,000
|
|
|
5,588,300,000
|
Long Term Debt, Fair Value |
|
5,267,700,000
|
|
|
5,267,700,000
|
|
|
5,390,100,000
|
Indiana Michigan Power Co [Member] |
|
|
|
|
|
|
|
|
Book Values and Fair Values of Long - term Debt |
|
|
|
|
|
|
|
|
Total Long-term Debt Outstanding |
|
3,540,300,000
|
|
|
3,540,300,000
|
|
|
3,499,400,000
|
Long Term Debt, Fair Value |
|
3,159,400,000
|
|
|
3,159,400,000
|
|
|
3,291,600,000
|
Nuclear Trust Fund Investments |
|
|
|
|
|
|
|
|
Fair Value |
|
4,214,000,000
|
|
|
4,214,000,000
|
|
|
3,860,200,000
|
Securities Activity Within Decommissioning and SNF Trusts |
|
|
|
|
|
|
|
|
Payments to Acquire Investments |
|
|
|
|
1,187,100,000
|
|
1,233,300,000
|
|
Contractual Maturities, Fair Value of Debt Securities |
|
|
|
|
|
|
|
|
Fair Value |
|
4,214,000,000
|
|
|
4,214,000,000
|
|
|
3,860,200,000
|
Indiana Michigan Power Co [Member] | Other [Member] |
|
|
|
|
|
|
|
|
Nuclear Trust Fund Investments |
|
|
|
|
|
|
|
|
Fair Value |
|
12,600,000
|
|
|
12,600,000
|
|
|
9,000,000.0
|
Contractual Maturities, Fair Value of Debt Securities |
|
|
|
|
|
|
|
|
Fair Value |
|
12,600,000
|
|
|
12,600,000
|
|
|
9,000,000.0
|
Indiana Michigan Power Co [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member] |
|
|
|
|
|
|
|
|
Securities Activity Within Decommissioning and SNF Trusts |
|
|
|
|
|
|
|
|
Payments to Acquire Investments |
|
598,600,000
|
|
697,000,000.0
|
1,187,100,000
|
|
1,233,300,000
|
|
Contractual Maturities, Fair Value of Debt Securities |
|
|
|
|
|
|
|
|
Within 1 year |
|
340,200,000
|
|
|
340,200,000
|
|
|
|
After 1 year through 5 years |
|
574,200,000
|
|
|
574,200,000
|
|
|
|
After 5 years through 10 years |
|
213,200,000
|
|
|
213,200,000
|
|
|
|
After 10 years |
|
264,900,000
|
|
|
264,900,000
|
|
|
|
Fair Value Measurements (Textuals) |
|
|
|
|
|
|
|
|
Adjusted Cost of Debt Securities |
|
1,400,000,000
|
|
|
1,400,000,000
|
|
|
1,400,000,000
|
Adjusted Cost of Domestic Equity Securities |
|
587,000,000
|
|
|
587,000,000
|
|
|
568,000,000
|
Other than Temporary Impairment Losses, Investments |
|
|
|
|
(27,400,000)
|
|
|
(41,800,000)
|
Proceeds from Sale of Other Investments |
|
584,600,000
|
|
688,700,000
|
1,154,100,000
|
|
1,206,300,000
|
|
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax |
|
(12,400,000)
|
|
|
(12,400,000)
|
|
|
(10,000,000.0)
|
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax |
|
2,229,100,000
|
|
|
2,229,100,000
|
|
|
1,902,900,000
|
Indiana Michigan Power Co [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member] | Gain [Member] |
|
|
|
|
|
|
|
|
Securities Activity Within Decommissioning and SNF Trusts |
|
|
|
|
|
|
|
|
Realized Investment Gains (Losses) |
|
4,900,000
|
|
6,400,000
|
10,300,000
|
|
54,800,000
|
|
Indiana Michigan Power Co [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member] | Loss [Member] |
|
|
|
|
|
|
|
|
Securities Activity Within Decommissioning and SNF Trusts |
|
|
|
|
|
|
|
|
Gain (Loss) on Investments |
|
4,200,000
|
|
$ 3,700,000
|
5,400,000
|
|
$ 12,300,000
|
|
Indiana Michigan Power Co [Member] | Fixed Income Funds [Member] |
|
|
|
|
|
|
|
|
Nuclear Trust Fund Investments |
|
|
|
|
|
|
|
|
Fair Value |
|
1,392,500,000
|
|
|
1,392,500,000
|
|
|
1,406,800,000
|
Contractual Maturities, Fair Value of Debt Securities |
|
|
|
|
|
|
|
|
Fair Value |
|
1,392,500,000
|
|
|
1,392,500,000
|
|
|
1,406,800,000
|
Indiana Michigan Power Co [Member] | Fixed Income Funds [Member] | Other [Member] |
|
|
|
|
|
|
|
|
Nuclear Trust Fund Investments |
|
|
|
|
|
|
|
|
Fair Value |
|
0
|
|
|
0
|
|
|
0
|
Contractual Maturities, Fair Value of Debt Securities |
|
|
|
|
|
|
|
|
Fair Value |
|
0
|
|
|
0
|
|
|
0
|
Indiana Michigan Power Co [Member] | Fixed Income Funds [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member] |
|
|
|
|
|
|
|
|
Fair Value Measurements (Textuals) |
|
|
|
|
|
|
|
|
Other than Temporary Impairment Losses, Investments |
|
|
|
|
(27,400,000)
|
|
|
(41,800,000)
|
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax |
|
(10,600,000)
|
|
|
(10,600,000)
|
|
|
(9,100,000)
|
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax |
|
15,100,000
|
|
|
15,100,000
|
|
|
33,400,000
|
Indiana Michigan Power Co [Member] | Domestic [Member] |
|
|
|
|
|
|
|
|
Nuclear Trust Fund Investments |
|
|
|
|
|
|
|
|
Fair Value |
[3] |
2,798,700,000
|
|
|
2,798,700,000
|
|
|
2,436,600,000
|
Contractual Maturities, Fair Value of Debt Securities |
|
|
|
|
|
|
|
|
Fair Value |
[3] |
2,798,700,000
|
|
|
2,798,700,000
|
|
|
2,436,600,000
|
Indiana Michigan Power Co [Member] | Domestic [Member] | Other [Member] |
|
|
|
|
|
|
|
|
Nuclear Trust Fund Investments |
|
|
|
|
|
|
|
|
Fair Value |
[3] |
0
|
|
|
0
|
|
|
0
|
Contractual Maturities, Fair Value of Debt Securities |
|
|
|
|
|
|
|
|
Fair Value |
[3] |
0
|
|
|
0
|
|
|
0
|
Indiana Michigan Power Co [Member] | Domestic [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member] |
|
|
|
|
|
|
|
|
Fair Value Measurements (Textuals) |
|
|
|
|
|
|
|
|
Other than Temporary Impairment Losses, Investments |
|
|
|
|
0
|
|
|
0
|
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax |
|
(1,800,000)
|
|
|
(1,800,000)
|
|
|
(900,000)
|
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax |
|
2,214,000,000
|
|
|
2,214,000,000
|
|
|
1,869,500,000
|
Indiana Michigan Power Co [Member] | Cash and Cash Equivalents [Member] |
|
|
|
|
|
|
|
|
Nuclear Trust Fund Investments |
|
|
|
|
|
|
|
|
Fair Value |
[4] |
22,800,000
|
|
|
22,800,000
|
|
|
16,800,000
|
Contractual Maturities, Fair Value of Debt Securities |
|
|
|
|
|
|
|
|
Fair Value |
[4] |
22,800,000
|
|
|
22,800,000
|
|
|
16,800,000
|
Indiana Michigan Power Co [Member] | Cash and Cash Equivalents [Member] | Other [Member] |
|
|
|
|
|
|
|
|
Nuclear Trust Fund Investments |
|
|
|
|
|
|
|
|
Fair Value |
[4] |
12,600,000
|
|
|
12,600,000
|
|
|
9,000,000.0
|
Contractual Maturities, Fair Value of Debt Securities |
|
|
|
|
|
|
|
|
Fair Value |
[4] |
12,600,000
|
|
|
12,600,000
|
|
|
9,000,000.0
|
Indiana Michigan Power Co [Member] | Cash and Cash Equivalents [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member] |
|
|
|
|
|
|
|
|
Fair Value Measurements (Textuals) |
|
|
|
|
|
|
|
|
Other than Temporary Impairment Losses, Investments |
|
|
|
|
0
|
|
|
0
|
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax |
|
0
|
|
|
0
|
|
|
0
|
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax |
|
0
|
|
|
0
|
|
|
0
|
Indiana Michigan Power Co [Member] | US Government Agencies Debt Securities [Member] |
|
|
|
|
|
|
|
|
Nuclear Trust Fund Investments |
|
|
|
|
|
|
|
|
Fair Value |
|
1,267,800,000
|
|
|
1,267,800,000
|
|
|
1,273,000,000
|
Contractual Maturities, Fair Value of Debt Securities |
|
|
|
|
|
|
|
|
Fair Value |
|
1,267,800,000
|
|
|
1,267,800,000
|
|
|
1,273,000,000
|
Indiana Michigan Power Co [Member] | US Government Agencies Debt Securities [Member] | Other [Member] |
|
|
|
|
|
|
|
|
Nuclear Trust Fund Investments |
|
|
|
|
|
|
|
|
Fair Value |
|
0
|
|
|
0
|
|
|
0
|
Contractual Maturities, Fair Value of Debt Securities |
|
|
|
|
|
|
|
|
Fair Value |
|
0
|
|
|
0
|
|
|
0
|
Indiana Michigan Power Co [Member] | US Government Agencies Debt Securities [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member] |
|
|
|
|
|
|
|
|
Fair Value Measurements (Textuals) |
|
|
|
|
|
|
|
|
Other than Temporary Impairment Losses, Investments |
|
|
|
|
(26,600,000)
|
|
|
(33,200,000)
|
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax |
|
(3,600,000)
|
|
|
(3,600,000)
|
|
|
(3,900,000)
|
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax |
|
13,800,000
|
|
|
13,800,000
|
|
|
28,600,000
|
Indiana Michigan Power Co [Member] | Corporate Debt [Member] |
|
|
|
|
|
|
|
|
Nuclear Trust Fund Investments |
|
|
|
|
|
|
|
|
Fair Value |
|
123,000,000.0
|
|
|
123,000,000.0
|
|
|
132,100,000
|
Contractual Maturities, Fair Value of Debt Securities |
|
|
|
|
|
|
|
|
Fair Value |
|
123,000,000.0
|
|
|
123,000,000.0
|
|
|
132,100,000
|
Indiana Michigan Power Co [Member] | Corporate Debt [Member] | Other [Member] |
|
|
|
|
|
|
|
|
Nuclear Trust Fund Investments |
|
|
|
|
|
|
|
|
Fair Value |
|
0
|
|
|
0
|
|
|
0
|
Contractual Maturities, Fair Value of Debt Securities |
|
|
|
|
|
|
|
|
Fair Value |
|
0
|
|
|
0
|
|
|
0
|
Indiana Michigan Power Co [Member] | Corporate Debt [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member] |
|
|
|
|
|
|
|
|
Fair Value Measurements (Textuals) |
|
|
|
|
|
|
|
|
Other than Temporary Impairment Losses, Investments |
|
|
|
|
(800,000)
|
|
|
(8,600,000)
|
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax |
|
(7,000,000.0)
|
|
|
(7,000,000.0)
|
|
|
(5,200,000)
|
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax |
|
1,300,000
|
|
|
1,300,000
|
|
|
4,800,000
|
Indiana Michigan Power Co [Member] | State and Local Jurisdiction [Member] |
|
|
|
|
|
|
|
|
Nuclear Trust Fund Investments |
|
|
|
|
|
|
|
|
Fair Value |
|
1,700,000
|
|
|
1,700,000
|
|
|
1,700,000
|
Contractual Maturities, Fair Value of Debt Securities |
|
|
|
|
|
|
|
|
Fair Value |
|
1,700,000
|
|
|
1,700,000
|
|
|
1,700,000
|
Indiana Michigan Power Co [Member] | State and Local Jurisdiction [Member] | Other [Member] |
|
|
|
|
|
|
|
|
Nuclear Trust Fund Investments |
|
|
|
|
|
|
|
|
Fair Value |
|
0
|
|
|
0
|
|
|
0
|
Contractual Maturities, Fair Value of Debt Securities |
|
|
|
|
|
|
|
|
Fair Value |
|
0
|
|
|
0
|
|
|
0
|
Indiana Michigan Power Co [Member] | State and Local Jurisdiction [Member] | Spent Nuclear Fuel and Decommissioning Trusts [Member] |
|
|
|
|
|
|
|
|
Fair Value Measurements (Textuals) |
|
|
|
|
|
|
|
|
Other than Temporary Impairment Losses, Investments |
|
|
|
|
0
|
|
|
0
|
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax |
|
0
|
|
|
0
|
|
|
0
|
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax |
|
0
|
|
|
0
|
|
|
0
|
Ohio Power Co [Member] |
|
|
|
|
|
|
|
|
Book Values and Fair Values of Long - term Debt |
|
|
|
|
|
|
|
|
Total Long-term Debt Outstanding |
|
3,714,300,000
|
|
|
3,714,300,000
|
|
|
3,366,800,000
|
Long Term Debt, Fair Value |
|
3,182,200,000
|
|
|
3,182,200,000
|
|
|
2,992,100,000
|
Public Service Co Of Oklahoma [Member] |
|
|
|
|
|
|
|
|
Book Values and Fair Values of Long - term Debt |
|
|
|
|
|
|
|
|
Total Long-term Debt Outstanding |
|
2,385,200,000
|
|
|
2,385,200,000
|
|
|
2,384,600,000
|
Long Term Debt, Fair Value |
|
2,084,500,000
|
|
|
2,084,500,000
|
|
|
2,154,300,000
|
Southwestern Electric Power Co [Member] |
|
|
|
|
|
|
|
|
Book Values and Fair Values of Long - term Debt |
|
|
|
|
|
|
|
|
Total Long-term Debt Outstanding |
|
3,648,300,000
|
|
|
3,648,300,000
|
|
|
3,646,900,000
|
Long Term Debt, Fair Value |
|
$ 3,114,400,000
|
|
|
$ 3,114,400,000
|
|
|
$ 3,209,700,000
|
|
|