Property, Plant and Equipment (Details) $ in Millions |
12 Months Ended |
Dec. 31, 2017
USD ($)
|
Dec. 31, 2016
USD ($)
|
Dec. 31, 2015
USD ($)
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Property, Plant and Equipment, Generation |
$ 20,760.5
|
|
$ 19,848.9
|
|
|
|
Property, Plant and Equipment, Transmission |
18,972.5
|
|
16,658.7
|
|
|
|
Property, Plant and Equipment, Distribution |
19,868.5
|
|
18,900.8
|
|
|
|
Property, Plant and Equipment, Other |
3,706.3
|
|
3,444.3
|
|
|
|
Property, Plant and Equipment, Construction Work in Progress |
4,120.7
|
|
3,183.9
|
|
|
|
Accumulated Depreciation |
17,167.0
|
|
16,397.3
|
|
|
|
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET |
50,261.5
|
|
45,639.3
|
[1] |
|
|
Asset Retirement Obligations (ARO) |
|
|
|
|
|
|
Beginning Balance |
1,934.9
|
[2],[3],[4],[5] |
1,916.3
|
[2],[3],[4],[5] |
|
|
Accretion Expense |
90.9
|
[2],[3],[4],[5] |
91.3
|
[2],[3],[4],[5] |
|
|
Liabilities Incurred |
2.4
|
[2],[3],[4],[5] |
0.8
|
[2],[3],[4],[5] |
|
|
Liabilities Settled |
(104.5)
|
[2],[3],[4],[5] |
(139.9)
|
[2],[3],[4],[5],[6] |
|
|
Revisions in Cash Flow Estimates |
82.0
|
[2],[3],[4],[5] |
66.4
|
[2],[3],[4],[5] |
|
|
Ending Balance |
2,005.7
|
[2],[3],[4],[5] |
1,934.9
|
[2],[3],[4],[5] |
$ 1,916.3
|
[2],[3],[4],[5] |
Allowance for Funds Used During Construction (AFUDC) and Interest Capitalization |
|
|
|
|
|
|
Allowance for Equity Funds Used During Construction |
93.7
|
|
113.2
|
|
131.9
|
|
Allowance for Borrowed Funds Used During Construction |
48.6
|
|
51.7
|
|
61.3
|
|
Jointly-owned Electric Facilities |
|
|
|
|
|
|
Utility Plant in Service |
3,399.3
|
|
3,458.2
|
|
|
|
Construction Work in Progress |
31.6
|
|
18.8
|
|
|
|
Accumulated Depreciation |
1,169.5
|
|
1,110.1
|
|
|
|
Asset Impairments and Other Related Charges |
87.1
|
|
2,267.8
|
|
0.0
|
|
Property, Plant and Equipment (Textuals) [Abstract] |
|
|
|
|
|
|
Asset Retirement Obligations (ARO) Liability for Nuclear Decommissioning of the Cook Plant |
1,300.0
|
|
1,240.0
|
|
|
|
Fair Value of Legally Restricted Assets |
2,220.0
|
|
1,950.0
|
|
|
|
AEP Texas Inc. [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Property, Plant and Equipment, Generation |
350.7
|
|
349.6
|
|
|
|
Property, Plant and Equipment, Transmission |
3,053.6
|
|
2,623.6
|
|
|
|
Property, Plant and Equipment, Distribution |
3,718.6
|
|
3,527.2
|
|
|
|
Property, Plant and Equipment, Other |
461.0
|
|
436.4
|
|
|
|
Property, Plant and Equipment, Construction Work in Progress |
835.7
|
|
385.9
|
|
|
|
Accumulated Depreciation |
1,594.5
|
|
1,542.0
|
|
|
|
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET |
6,825.1
|
|
5,780.7
|
|
|
|
Asset Retirement Obligations (ARO) |
|
|
|
|
|
|
Beginning Balance |
25.5
|
[3],[4] |
24.0
|
[3],[4] |
|
|
Accretion Expense |
1.2
|
[3],[4] |
1.1
|
[3],[4] |
|
|
Liabilities Incurred |
0.0
|
[3],[4] |
0.0
|
[3],[4] |
|
|
Liabilities Settled |
(0.1)
|
[3],[4] |
(0.1)
|
[3],[4] |
|
|
Revisions in Cash Flow Estimates |
0.1
|
[3],[4] |
0.5
|
[3],[4] |
|
|
Ending Balance |
26.7
|
[3],[4] |
25.5
|
[3],[4] |
24.0
|
[3],[4] |
Allowance for Funds Used During Construction (AFUDC) and Interest Capitalization |
|
|
|
|
|
|
Allowance for Equity Funds Used During Construction |
6.8
|
|
9.2
|
|
6.7
|
|
Allowance for Borrowed Funds Used During Construction |
$ 6.8
|
|
5.9
|
|
4.5
|
|
Jointly-owned Electric Facilities |
|
|
|
|
|
|
Percent of Ownership |
54.69%
|
|
|
|
|
|
Asset Impairments and Other Related Charges |
|
|
72.7
|
|
0.0
|
|
AEP Transmission Co [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Property, Plant and Equipment, Transmission |
$ 5,336.1
|
|
3,973.5
|
|
|
|
Property, Plant and Equipment, Other |
131.4
|
|
99.4
|
|
|
|
Property, Plant and Equipment, Construction Work in Progress |
1,312.7
|
|
981.3
|
|
|
|
Accumulated Depreciation |
170.4
|
|
99.6
|
|
|
|
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET |
6,609.8
|
|
4,954.6
|
|
|
|
Allowance for Funds Used During Construction (AFUDC) and Interest Capitalization |
|
|
|
|
|
|
Allowance for Equity Funds Used During Construction |
52.3
|
|
52.3
|
|
53.0
|
|
Allowance for Borrowed Funds Used During Construction |
20.2
|
|
15.6
|
|
17.7
|
|
Appalachian Power Co [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Property, Plant and Equipment, Generation |
6,446.9
|
|
6,332.8
|
|
|
|
Property, Plant and Equipment, Transmission |
3,019.9
|
|
2,796.9
|
|
|
|
Property, Plant and Equipment, Distribution |
3,763.8
|
|
3,569.1
|
|
|
|
Property, Plant and Equipment, Other |
427.9
|
|
373.5
|
|
|
|
Property, Plant and Equipment, Construction Work in Progress |
483.0
|
|
390.3
|
|
|
|
Accumulated Depreciation |
3,896.4
|
|
3,636.8
|
|
|
|
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET |
10,245.1
|
|
9,825.8
|
|
|
|
Asset Retirement Obligations (ARO) |
|
|
|
|
|
|
Beginning Balance |
127.1
|
[3],[4] |
140.2
|
[3],[4] |
|
|
Accretion Expense |
7.0
|
[3],[4] |
7.6
|
[3],[4] |
|
|
Liabilities Incurred |
0.0
|
[3],[4] |
0.0
|
[3],[4] |
|
|
Liabilities Settled |
(21.7)
|
[3],[4] |
(35.3)
|
[3],[4] |
|
|
Revisions in Cash Flow Estimates |
12.6
|
[3],[4] |
14.6
|
[3],[4] |
|
|
Ending Balance |
125.0
|
[3],[4] |
127.1
|
[3],[4] |
140.2
|
[3],[4] |
Allowance for Funds Used During Construction (AFUDC) and Interest Capitalization |
|
|
|
|
|
|
Allowance for Equity Funds Used During Construction |
9.2
|
|
11.7
|
|
13.8
|
|
Allowance for Borrowed Funds Used During Construction |
5.3
|
|
6.3
|
|
6.9
|
|
Indiana Michigan Power Co [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Property, Plant and Equipment, Generation |
4,445.9
|
|
4,056.1
|
|
|
|
Property, Plant and Equipment, Transmission |
1,504.0
|
|
1,472.8
|
|
|
|
Property, Plant and Equipment, Distribution |
2,069.3
|
|
1,899.3
|
|
|
|
Property, Plant and Equipment, Other |
595.2
|
|
550.2
|
|
|
|
Property, Plant and Equipment, Construction Work in Progress |
460.2
|
|
654.2
|
|
|
|
Accumulated Depreciation |
3,024.2
|
|
3,005.1
|
|
|
|
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET |
6,050.4
|
|
5,627.5
|
|
|
|
Asset Retirement Obligations (ARO) |
|
|
|
|
|
|
Beginning Balance |
1,258.1
|
[3],[4],[5] |
1,253.8
|
[3],[4],[5] |
|
|
Accretion Expense |
55.9
|
[3],[4],[5] |
55.6
|
[3],[4],[5] |
|
|
Liabilities Incurred |
0.0
|
[3],[4],[5] |
0.0
|
[3],[4],[5] |
|
|
Liabilities Settled |
(0.1)
|
[3],[4],[5] |
(62.6)
|
[3],[4],[5],[6] |
|
|
Revisions in Cash Flow Estimates |
7.9
|
[3],[4],[5] |
11.3
|
[3],[4],[5] |
|
|
Ending Balance |
1,321.8
|
[3],[4],[5] |
1,258.1
|
[3],[4],[5] |
1,253.8
|
[3],[4],[5] |
Allowance for Funds Used During Construction (AFUDC) and Interest Capitalization |
|
|
|
|
|
|
Allowance for Equity Funds Used During Construction |
11.1
|
|
15.3
|
|
11.6
|
|
Allowance for Borrowed Funds Used During Construction |
6.7
|
|
7.2
|
|
5.0
|
|
Jointly-owned Electric Facilities |
|
|
|
|
|
|
Asset Impairments and Other Related Charges |
0.0
|
|
10.5
|
|
0.0
|
|
Property, Plant and Equipment (Textuals) [Abstract] |
|
|
|
|
|
|
Asset Retirement Obligations (ARO) Liability for Nuclear Decommissioning of the Cook Plant |
1,300.0
|
[5] |
1,240.0
|
[5] |
|
|
Fair Value of Legally Restricted Assets |
2,220.0
|
|
1,950.0
|
|
|
|
Ohio Power Co [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Property, Plant and Equipment, Transmission |
2,419.2
|
|
2,319.2
|
|
|
|
Property, Plant and Equipment, Distribution |
4,626.4
|
|
4,457.2
|
|
|
|
Property, Plant and Equipment, Other |
495.9
|
|
443.7
|
|
|
|
Property, Plant and Equipment, Construction Work in Progress |
410.1
|
|
221.5
|
|
|
|
Accumulated Depreciation |
2,184.8
|
|
2,116.0
|
|
|
|
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET |
5,766.8
|
|
5,325.6
|
|
|
|
Asset Retirement Obligations (ARO) |
|
|
|
|
|
|
Beginning Balance |
1.7
|
[3] |
1.4
|
[3] |
|
|
Accretion Expense |
0.1
|
[3] |
0.1
|
[3] |
|
|
Liabilities Incurred |
0.0
|
[3] |
0.2
|
[3] |
|
|
Liabilities Settled |
(0.1)
|
[3] |
0.0
|
[3] |
|
|
Revisions in Cash Flow Estimates |
0.0
|
[3] |
0.0
|
[3] |
|
|
Ending Balance |
1.7
|
[3] |
1.7
|
[3] |
1.4
|
[3] |
Allowance for Funds Used During Construction (AFUDC) and Interest Capitalization |
|
|
|
|
|
|
Allowance for Equity Funds Used During Construction |
6.4
|
|
6.0
|
|
8.8
|
|
Allowance for Borrowed Funds Used During Construction |
3.8
|
|
3.3
|
|
4.8
|
|
Public Service Co Of Oklahoma [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Property, Plant and Equipment, Generation |
1,577.2
|
|
1,559.3
|
|
|
|
Property, Plant and Equipment, Transmission |
858.8
|
|
832.8
|
|
|
|
Property, Plant and Equipment, Distribution |
2,445.1
|
|
2,322.4
|
|
|
|
Property, Plant and Equipment, Other |
287.4
|
|
233.2
|
|
|
|
Property, Plant and Equipment, Construction Work in Progress |
111.3
|
|
148.2
|
|
|
|
Accumulated Depreciation |
1,393.6
|
|
1,272.7
|
|
|
|
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET |
3,886.2
|
|
3,823.2
|
|
|
|
Asset Retirement Obligations (ARO) |
|
|
|
|
|
|
Beginning Balance |
53.4
|
[3],[4] |
47.8
|
[3],[4] |
|
|
Accretion Expense |
3.1
|
[3],[4] |
3.0
|
[3],[4] |
|
|
Liabilities Incurred |
0.0
|
[3],[4] |
0.1
|
[3],[4] |
|
|
Liabilities Settled |
(0.5)
|
[3],[4] |
(1.0)
|
[3],[4] |
|
|
Revisions in Cash Flow Estimates |
(2.0)
|
[3],[4] |
3.5
|
[3],[4] |
|
|
Ending Balance |
54.0
|
[3],[4] |
53.4
|
[3],[4] |
47.8
|
[3],[4] |
Allowance for Funds Used During Construction (AFUDC) and Interest Capitalization |
|
|
|
|
|
|
Allowance for Equity Funds Used During Construction |
0.5
|
|
6.2
|
|
8.8
|
|
Allowance for Borrowed Funds Used During Construction |
1.1
|
|
3.4
|
|
5.0
|
|
Southwestern Electric Power Co [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Property, Plant and Equipment, Generation |
4,624.9
|
|
4,607.6
|
|
|
|
Property, Plant and Equipment, Transmission |
1,679.8
|
|
1,584.2
|
|
|
|
Property, Plant and Equipment, Distribution |
2,095.8
|
|
2,020.6
|
|
|
|
Property, Plant and Equipment, Other |
684.1
|
|
670.4
|
|
|
|
Property, Plant and Equipment, Construction Work in Progress |
233.2
|
|
113.8
|
|
|
|
Accumulated Depreciation |
2,685.8
|
|
2,567.1
|
|
|
|
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET |
6,632.0
|
|
6,429.5
|
|
|
|
Asset Retirement Obligations (ARO) |
|
|
|
|
|
|
Beginning Balance |
156.5
|
[2],[3],[4] |
125.4
|
[2],[3],[4] |
|
|
Accretion Expense |
8.3
|
[2],[3],[4] |
7.0
|
[2],[3],[4] |
|
|
Liabilities Incurred |
0.0
|
[2],[3],[4] |
0.2
|
[2],[3],[4] |
|
|
Liabilities Settled |
(0.3)
|
[2],[3],[4] |
(8.3)
|
[2],[3],[4] |
|
|
Revisions in Cash Flow Estimates |
4.7
|
[2],[3],[4] |
32.2
|
[2],[3],[4] |
|
|
Ending Balance |
169.2
|
[2],[3],[4] |
156.5
|
[2],[3],[4] |
125.4
|
[2],[3],[4] |
Allowance for Funds Used During Construction (AFUDC) and Interest Capitalization |
|
|
|
|
|
|
Allowance for Equity Funds Used During Construction |
2.4
|
|
11.0
|
|
26.4
|
|
Allowance for Borrowed Funds Used During Construction |
2.1
|
|
6.9
|
|
14.8
|
|
Jointly-owned Electric Facilities |
|
|
|
|
|
|
Utility Plant in Service |
2,878.1
|
|
2,940.9
|
|
|
|
Construction Work in Progress |
25.2
|
|
14.6
|
|
|
|
Accumulated Depreciation |
868.7
|
|
819.0
|
|
|
|
Asset Impairments and Other Related Charges |
$ 33.6
|
|
$ 0.0
|
|
$ 0.0
|
|
Conesville Generating Station (Unit No. 4) [Member] |
|
|
|
|
|
|
Jointly-owned Electric Facilities |
|
|
|
|
|
|
Percent of Ownership |
83.50%
|
|
|
|
|
|
Acquired Ownership Interest |
40.00%
|
|
|
|
|
|
Conesville Generating Station (Unit No. 4) [Member] | Coal [Member] |
|
|
|
|
|
|
Jointly-owned Electric Facilities |
|
|
|
|
|
|
Percent of Ownership |
83.50%
|
[7],[8],[9] |
43.50%
|
[7],[8],[9] |
|
|
Utility Plant in Service |
$ 2.1
|
[7],[8],[9] |
$ 0.1
|
[7],[8],[9] |
|
|
Construction Work in Progress |
4.2
|
[7],[8],[9] |
1.3
|
[7],[8],[9] |
|
|
Accumulated Depreciation |
$ 0.1
|
[7],[8],[9] |
$ 0.0
|
[7],[8],[9] |
|
|
J.M. Stuart Generating Station [Member] | Coal [Member] |
|
|
|
|
|
|
Jointly-owned Electric Facilities |
|
|
|
|
|
|
Percent of Ownership |
26.00%
|
[7],[10] |
26.00%
|
[7],[10] |
|
|
Utility Plant in Service |
$ 0.0
|
[7],[10] |
$ 0.0
|
[7],[10] |
|
|
Construction Work in Progress |
0.0
|
[7],[10] |
0.8
|
[7],[10] |
|
|
Accumulated Depreciation |
$ 0.0
|
[7],[10] |
$ 0.0
|
[7],[10] |
|
|
Wm. H. Zimmer Generating Station [Member] |
|
|
|
|
|
|
Jointly-owned Electric Facilities |
|
|
|
|
|
|
Percent of Ownership |
25.40%
|
|
|
|
|
|
Wm. H. Zimmer Generating Station [Member] | Coal [Member] |
|
|
|
|
|
|
Jointly-owned Electric Facilities |
|
|
|
|
|
|
Percent of Ownership |
|
|
25.40%
|
[7],[11],[12] |
|
|
Utility Plant in Service |
|
|
$ 0.0
|
[7],[11],[12] |
|
|
Construction Work in Progress |
|
|
0.3
|
[7],[11],[12] |
|
|
Accumulated Depreciation |
|
|
$ 0.0
|
[7],[11],[12] |
|
|
Dolet Hills Generating Station (Unit No. 1) [Member] | Public Utilities, Inventory, Lignite [Member] |
|
|
|
|
|
|
Jointly-owned Electric Facilities |
|
|
|
|
|
|
Percent of Ownership |
40.20%
|
[13] |
40.20%
|
[13] |
|
|
Utility Plant in Service |
$ 343.1
|
[13] |
$ 334.8
|
[13] |
|
|
Construction Work in Progress |
5.3
|
[13] |
5.0
|
[13] |
|
|
Accumulated Depreciation |
$ 214.2
|
[13] |
$ 207.5
|
[13] |
|
|
Dolet Hills Generating Station (Unit No. 1) [Member] | Southwestern Electric Power Co [Member] | Public Utilities, Inventory, Lignite [Member] |
|
|
|
|
|
|
Jointly-owned Electric Facilities |
|
|
|
|
|
|
Percent of Ownership |
40.20%
|
[13] |
40.20%
|
[13] |
|
|
Utility Plant in Service |
$ 343.1
|
[13] |
$ 334.8
|
[13] |
|
|
Construction Work in Progress |
5.3
|
[13] |
5.0
|
[13] |
|
|
Accumulated Depreciation |
$ 214.2
|
[13] |
$ 207.5
|
[13] |
|
|
Flint Creek Generating Station (Unit No. 1) [Member] | Coal [Member] |
|
|
|
|
|
|
Jointly-owned Electric Facilities |
|
|
|
|
|
|
Percent of Ownership |
50.00%
|
[14] |
50.00%
|
[14] |
|
|
Utility Plant in Service |
$ 364.8
|
[14] |
$ 362.4
|
[14] |
|
|
Construction Work in Progress |
8.9
|
[14] |
3.7
|
[14] |
|
|
Accumulated Depreciation |
$ 81.6
|
[14] |
$ 73.5
|
[14] |
|
|
Flint Creek Generating Station (Unit No. 1) [Member] | Southwestern Electric Power Co [Member] | Coal [Member] |
|
|
|
|
|
|
Jointly-owned Electric Facilities |
|
|
|
|
|
|
Percent of Ownership |
50.00%
|
[14] |
50.00%
|
[14] |
|
|
Utility Plant in Service |
$ 364.8
|
[14] |
$ 362.4
|
[14] |
|
|
Construction Work in Progress |
8.9
|
[14] |
3.7
|
[14] |
|
|
Accumulated Depreciation |
$ 81.6
|
[14] |
$ 73.5
|
[14] |
|
|
Pirkey Generating Station (Unit No. 1) [Member] | Public Utilities, Inventory, Lignite [Member] |
|
|
|
|
|
|
Jointly-owned Electric Facilities |
|
|
|
|
|
|
Percent of Ownership |
85.90%
|
[14] |
85.90%
|
[14] |
|
|
Utility Plant in Service |
$ 589.8
|
[14] |
$ 586.4
|
[14] |
|
|
Construction Work in Progress |
7.8
|
[14] |
5.7
|
[14] |
|
|
Accumulated Depreciation |
$ 406.3
|
[14] |
$ 399.5
|
[14] |
|
|
Pirkey Generating Station (Unit No. 1) [Member] | Southwestern Electric Power Co [Member] | Public Utilities, Inventory, Lignite [Member] |
|
|
|
|
|
|
Jointly-owned Electric Facilities |
|
|
|
|
|
|
Percent of Ownership |
85.90%
|
[14] |
85.90%
|
[14] |
|
|
Utility Plant in Service |
$ 589.8
|
[14] |
$ 586.4
|
[14] |
|
|
Construction Work in Progress |
7.8
|
[14] |
5.7
|
[14] |
|
|
Accumulated Depreciation |
$ 406.3
|
[14] |
$ 399.5
|
[14] |
|
|
Oklaunion Generating Station (Unit No. 1) [Member] | Coal [Member] |
|
|
|
|
|
|
Jointly-owned Electric Facilities |
|
|
|
|
|
|
Percent of Ownership |
70.30%
|
[15] |
70.30%
|
[15] |
|
|
Utility Plant in Service |
$ 456.4
|
[15] |
$ 454.8
|
[15] |
|
|
Construction Work in Progress |
1.9
|
[15] |
1.3
|
[15] |
|
|
Accumulated Depreciation |
$ 254.6
|
[15] |
$ 246.0
|
[15] |
|
|
Oklaunion Generating Station (Unit No. 1) [Member] | AEP Texas Inc. [Member] |
|
|
|
|
|
|
Jointly-owned Electric Facilities |
|
|
|
|
|
|
Percent of Ownership |
54.70%
|
|
|
|
|
|
Oklaunion Generating Station (Unit No. 1) [Member] | AEP Texas Inc. [Member] | Coal [Member] |
|
|
|
|
|
|
Jointly-owned Electric Facilities |
|
|
|
|
|
|
Percent of Ownership |
54.70%
|
[15] |
54.70%
|
[15] |
|
|
Utility Plant in Service |
$ 350.7
|
[15] |
$ 349.6
|
[15] |
|
|
Construction Work in Progress |
1.3
|
[15] |
0.9
|
[15] |
|
|
Accumulated Depreciation |
$ 194.1
|
[15] |
$ 186.5
|
[15] |
|
|
Oklaunion Generating Station (Unit No. 1) [Member] | Public Service Co Of Oklahoma [Member] |
|
|
|
|
|
|
Jointly-owned Electric Facilities |
|
|
|
|
|
|
Percent of Ownership |
15.60%
|
|
|
|
|
|
Oklaunion Generating Station (Unit No. 1) [Member] | Public Service Co Of Oklahoma [Member] | Coal [Member] |
|
|
|
|
|
|
Jointly-owned Electric Facilities |
|
|
|
|
|
|
Percent of Ownership |
15.60%
|
[15] |
15.60%
|
[15] |
|
|
Utility Plant in Service |
$ 105.7
|
[15] |
$ 105.2
|
[15] |
|
|
Construction Work in Progress |
0.6
|
[15] |
0.5
|
[15] |
|
|
Accumulated Depreciation |
$ 60.5
|
[15] |
$ 59.4
|
[15] |
|
|
Turk Generating Plant [Member] | Coal [Member] |
|
|
|
|
|
|
Jointly-owned Electric Facilities |
|
|
|
|
|
|
Percent of Ownership |
73.30%
|
[14],[16] |
73.30%
|
[14] |
|
|
Utility Plant in Service |
$ 1,580.4
|
[14],[16] |
$ 1,657.3
|
[14] |
|
|
Construction Work in Progress |
3.2
|
[14],[16] |
0.2
|
[14] |
|
|
Accumulated Depreciation |
166.6
|
[14],[16] |
$ 138.5
|
[14] |
|
|
Turk Generating Plant [Member] | Southwestern Electric Power Co [Member] |
|
|
|
|
|
|
Jointly-owned Electric Facilities |
|
|
|
|
|
|
Asset Impairments and Other Related Charges |
$ 15.0
|
|
|
|
|
|
Turk Generating Plant [Member] | Southwestern Electric Power Co [Member] | Coal [Member] |
|
|
|
|
|
|
Jointly-owned Electric Facilities |
|
|
|
|
|
|
Percent of Ownership |
73.30%
|
[14],[16] |
73.30%
|
[14] |
|
|
Utility Plant in Service |
$ 1,580.4
|
[14],[16] |
$ 1,657.3
|
[14] |
|
|
Construction Work in Progress |
3.2
|
[14],[16] |
0.2
|
[14] |
|
|
Accumulated Depreciation |
$ 166.6
|
[14],[16] |
$ 138.5
|
[14] |
|
|
Jointly Owned Electricity Transmission and Distribution System [Member] |
|
|
|
|
|
|
Jointly-owned Electric Facilities |
|
|
|
|
|
|
Percent of Ownership |
|
[17] |
|
[17] |
|
|
Utility Plant in Service |
$ 62.7
|
|
$ 62.4
|
|
|
|
Construction Work in Progress |
0.3
|
|
0.5
|
|
|
|
Accumulated Depreciation |
$ 46.1
|
|
$ 45.1
|
|
|
|
Rockport Generating Plant (Unit No. 1) [Member] | Indiana Michigan Power Co [Member] |
|
|
|
|
|
|
Jointly-owned Electric Facilities |
|
|
|
|
|
|
Percent of Ownership |
50.00%
|
|
|
|
|
|
Rockport Generating Plant (Unit No. 1) [Member] | Indiana Michigan Power Co [Member] | Coal [Member] |
|
|
|
|
|
|
Jointly-owned Electric Facilities |
|
|
|
|
|
|
Percent of Ownership |
50.00%
|
[18],[19],[20] |
50.00%
|
[18],[19],[20] |
|
|
Utility Plant in Service |
$ 1,093.9
|
[18],[19],[20] |
$ 936.1
|
[18],[19],[20] |
|
|
Construction Work in Progress |
28.2
|
[18],[19],[20] |
125.8
|
[18],[19],[20] |
|
|
Accumulated Depreciation |
$ 562.6
|
[18],[19],[20] |
535.1
|
[18],[19],[20] |
|
|
Rockport Generating Plant (Unit No. 1) [Member] | AEP Generating Co [Member] |
|
|
|
|
|
|
Jointly-owned Electric Facilities |
|
|
|
|
|
|
Percent of Ownership |
50.00%
|
|
|
|
|
|
Rockport Generating Plant (Unit No. 2) [Member] | AEP Generating Co [Member] |
|
|
|
|
|
|
Jointly-owned Electric Facilities |
|
|
|
|
|
|
Percent of Ownership |
50.00%
|
|
|
|
|
|
Regulated Operation [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Property, Plant and Equipment, Generation |
$ 20,406.5
|
[21] |
19,703.9
|
[21] |
|
|
Property, Plant and Equipment, Transmission |
18,942.3
|
|
16,658.6
|
|
|
|
Property, Plant and Equipment, Distribution |
19,865.9
|
|
18,898.2
|
|
|
|
Property, Plant and Equipment, Other |
3,224.8
|
|
2,902.0
|
|
|
|
Property, Plant and Equipment, Construction Work in Progress |
3,972.6
|
[21] |
3,072.2
|
[21] |
|
|
Accumulated Depreciation |
16,906.7
|
|
16,101.5
|
|
|
|
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET |
$ 49,505.4
|
|
$ 45,133.4
|
|
|
|
Regulated Operation [Member] | Maximum [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Depreciable Life Ranges - Generation |
132 years
|
|
132 years
|
|
132 years
|
|
Depreciable Life Ranges - Transmission |
100 years
|
|
100 years
|
|
81 years
|
|
Depreciable Life Ranges - Distribution |
156 years
|
|
156 years
|
|
75 years
|
|
Depreciable Life Ranges - Other |
84 years
|
|
84 years
|
|
75 years
|
|
Regulated Operation [Member] | Minimum [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Depreciable Life Ranges - Generation |
20 years
|
|
35 years
|
|
35 years
|
|
Depreciable Life Ranges - Transmission |
15 years
|
|
15 years
|
|
15 years
|
|
Depreciable Life Ranges - Distribution |
5 years
|
|
7 years
|
|
7 years
|
|
Depreciable Life Ranges - Other |
5 years
|
|
5 years
|
|
5 years
|
|
Regulated Operation [Member] | Generation [Member] | Maximum [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Annual Composite Depreciation Rate |
3.70%
|
|
4.00%
|
|
3.10%
|
|
Regulated Operation [Member] | Generation [Member] | Minimum [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Annual Composite Depreciation Rate |
2.30%
|
|
2.10%
|
|
0.40%
|
|
Regulated Operation [Member] | Transmission [Member] | Maximum [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Annual Composite Depreciation Rate |
2.70%
|
|
2.70%
|
|
2.70%
|
|
Regulated Operation [Member] | Transmission [Member] | Minimum [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Annual Composite Depreciation Rate |
1.60%
|
|
1.50%
|
|
1.40%
|
|
Regulated Operation [Member] | Distribution [Member] | Maximum [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Annual Composite Depreciation Rate |
3.70%
|
|
3.70%
|
|
3.70%
|
|
Regulated Operation [Member] | Distribution [Member] | Minimum [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Annual Composite Depreciation Rate |
2.70%
|
|
2.60%
|
|
2.50%
|
|
Regulated Operation [Member] | Other Property Class [Member] | Maximum [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Annual Composite Depreciation Rate |
9.20%
|
|
8.60%
|
|
11.80%
|
|
Regulated Operation [Member] | Other Property Class [Member] | Minimum [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Annual Composite Depreciation Rate |
2.30%
|
|
3.10%
|
|
2.90%
|
|
Regulated Operation [Member] | AEP Texas Inc. [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Property, Plant and Equipment, Generation |
$ 0.0
|
|
$ 0.0
|
|
|
|
Property, Plant and Equipment, Transmission |
3,053.6
|
|
2,623.6
|
|
|
|
Property, Plant and Equipment, Distribution |
3,718.6
|
|
3,527.2
|
|
|
|
Property, Plant and Equipment, Other |
457.6
|
|
432.1
|
|
|
|
Property, Plant and Equipment, Construction Work in Progress |
834.4
|
|
385.0
|
|
|
|
Accumulated Depreciation |
1,399.4
|
|
1,354.4
|
|
|
|
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET |
$ 6,664.8
|
|
$ 5,613.5
|
|
|
|
Regulated Operation [Member] | AEP Texas Inc. [Member] | Maximum [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Depreciable Life Ranges - Transmission |
81 years
|
|
81 years
|
|
81 years
|
|
Depreciable Life Ranges - Distribution |
70 years
|
|
70 years
|
|
70 years
|
|
Depreciable Life Ranges - Other |
50 years
|
|
50 years
|
|
50 years
|
|
Regulated Operation [Member] | AEP Texas Inc. [Member] | Minimum [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Depreciable Life Ranges - Transmission |
45 years
|
|
45 years
|
|
45 years
|
|
Depreciable Life Ranges - Distribution |
7 years
|
|
7 years
|
|
7 years
|
|
Depreciable Life Ranges - Other |
5 years
|
|
5 years
|
|
5 years
|
|
Regulated Operation [Member] | AEP Texas Inc. [Member] | Transmission [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Annual Composite Depreciation Rate |
1.70%
|
|
1.80%
|
|
1.80%
|
|
Regulated Operation [Member] | AEP Texas Inc. [Member] | Distribution [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Annual Composite Depreciation Rate |
3.60%
|
|
3.30%
|
|
3.30%
|
|
Regulated Operation [Member] | AEP Texas Inc. [Member] | Other Property Class [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Annual Composite Depreciation Rate |
8.70%
|
|
8.30%
|
|
9.70%
|
|
Regulated Operation [Member] | AEP Transmission Co [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Property, Plant and Equipment, Generation |
$ 0.0
|
|
$ 0.0
|
|
|
|
Property, Plant and Equipment, Transmission |
5,336.1
|
|
3,973.5
|
|
|
|
Property, Plant and Equipment, Distribution |
0.0
|
|
0.0
|
|
|
|
Property, Plant and Equipment, Other |
130.0
|
|
98.3
|
|
|
|
Property, Plant and Equipment, Construction Work in Progress |
1,312.7
|
|
981.3
|
|
|
|
Accumulated Depreciation |
170.4
|
|
99.6
|
|
|
|
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET |
$ 6,608.4
|
|
$ 4,953.5
|
|
|
|
Regulated Operation [Member] | AEP Transmission Co [Member] | Maximum [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Depreciable Life Ranges - Transmission |
100 years
|
|
100 years
|
|
75 years
|
|
Regulated Operation [Member] | AEP Transmission Co [Member] | Minimum [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Depreciable Life Ranges - Transmission |
20 years
|
|
20 years
|
|
20 years
|
|
Regulated Operation [Member] | AEP Transmission Co [Member] | Transmission [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Annual Composite Depreciation Rate |
1.70%
|
|
1.60%
|
|
1.40%
|
|
Regulated Operation [Member] | Appalachian Power Co [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Property, Plant and Equipment, Generation |
$ 6,446.9
|
|
$ 6,332.8
|
|
|
|
Property, Plant and Equipment, Transmission |
3,019.9
|
|
2,796.9
|
|
|
|
Property, Plant and Equipment, Distribution |
3,763.8
|
|
3,569.1
|
|
|
|
Property, Plant and Equipment, Other |
399.5
|
|
345.1
|
|
|
|
Property, Plant and Equipment, Construction Work in Progress |
483.0
|
|
390.3
|
|
|
|
Accumulated Depreciation |
3,891.1
|
|
3,631.5
|
|
|
|
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET |
$ 10,222.0
|
|
$ 9,802.7
|
|
|
|
Regulated Operation [Member] | Appalachian Power Co [Member] | Maximum [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Depreciable Life Ranges - Generation |
112 years
|
|
121 years
|
|
121 years
|
|
Depreciable Life Ranges - Transmission |
68 years
|
|
68 years
|
|
68 years
|
|
Depreciable Life Ranges - Distribution |
57 years
|
|
57 years
|
|
57 years
|
|
Depreciable Life Ranges - Other |
55 years
|
|
55 years
|
|
55 years
|
|
Regulated Operation [Member] | Appalachian Power Co [Member] | Minimum [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Depreciable Life Ranges - Generation |
35 years
|
|
35 years
|
|
35 years
|
|
Depreciable Life Ranges - Transmission |
15 years
|
|
15 years
|
|
15 years
|
|
Depreciable Life Ranges - Distribution |
10 years
|
|
10 years
|
|
10 years
|
|
Depreciable Life Ranges - Other |
5 years
|
|
5 years
|
|
5 years
|
|
Regulated Operation [Member] | Appalachian Power Co [Member] | Generation [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Annual Composite Depreciation Rate |
3.10%
|
|
3.10%
|
|
3.10%
|
|
Regulated Operation [Member] | Appalachian Power Co [Member] | Transmission [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Annual Composite Depreciation Rate |
1.60%
|
|
1.50%
|
|
1.60%
|
|
Regulated Operation [Member] | Appalachian Power Co [Member] | Distribution [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Annual Composite Depreciation Rate |
3.70%
|
|
3.70%
|
|
3.60%
|
|
Regulated Operation [Member] | Appalachian Power Co [Member] | Other Property Class [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Annual Composite Depreciation Rate |
6.50%
|
|
6.00%
|
|
8.30%
|
|
Regulated Operation [Member] | Indiana Michigan Power Co [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Property, Plant and Equipment, Generation |
$ 4,445.9
|
|
$ 4,056.1
|
|
|
|
Property, Plant and Equipment, Transmission |
1,504.0
|
|
1,472.8
|
|
|
|
Property, Plant and Equipment, Distribution |
2,069.3
|
|
1,899.3
|
|
|
|
Property, Plant and Equipment, Other |
552.3
|
|
507.7
|
|
|
|
Property, Plant and Equipment, Construction Work in Progress |
460.2
|
|
654.2
|
|
|
|
Accumulated Depreciation |
3,011.7
|
|
2,989.9
|
|
|
|
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET |
$ 6,020.0
|
|
$ 5,600.2
|
|
|
|
Regulated Operation [Member] | Indiana Michigan Power Co [Member] | Maximum [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Depreciable Life Ranges - Generation |
132 years
|
|
132 years
|
|
132 years
|
|
Depreciable Life Ranges - Transmission |
75 years
|
|
75 years
|
|
75 years
|
|
Depreciable Life Ranges - Distribution |
70 years
|
|
70 years
|
|
70 years
|
|
Depreciable Life Ranges - Other |
45 years
|
|
45 years
|
|
45 years
|
|
Regulated Operation [Member] | Indiana Michigan Power Co [Member] | Minimum [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Depreciable Life Ranges - Generation |
20 years
|
|
59 years
|
|
59 years
|
|
Depreciable Life Ranges - Transmission |
50 years
|
|
50 years
|
|
50 years
|
|
Depreciable Life Ranges - Distribution |
10 years
|
|
10 years
|
|
10 years
|
|
Depreciable Life Ranges - Other |
5 years
|
|
5 years
|
|
5 years
|
|
Regulated Operation [Member] | Indiana Michigan Power Co [Member] | Generation [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Annual Composite Depreciation Rate |
2.40%
|
|
2.40%
|
|
2.50%
|
|
Regulated Operation [Member] | Indiana Michigan Power Co [Member] | Transmission [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Annual Composite Depreciation Rate |
1.70%
|
|
1.70%
|
|
1.70%
|
|
Regulated Operation [Member] | Indiana Michigan Power Co [Member] | Distribution [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Annual Composite Depreciation Rate |
2.70%
|
|
2.80%
|
|
2.80%
|
|
Regulated Operation [Member] | Indiana Michigan Power Co [Member] | Other Property Class [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Annual Composite Depreciation Rate |
8.40%
|
|
8.60%
|
|
11.80%
|
|
Regulated Operation [Member] | Ohio Power Co [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Property, Plant and Equipment, Generation |
$ 0.0
|
|
$ 0.0
|
|
|
|
Property, Plant and Equipment, Transmission |
2,419.2
|
|
2,319.2
|
|
|
|
Property, Plant and Equipment, Distribution |
4,626.4
|
|
4,457.2
|
|
|
|
Property, Plant and Equipment, Other |
485.5
|
|
433.4
|
|
|
|
Property, Plant and Equipment, Construction Work in Progress |
410.1
|
|
221.5
|
|
|
|
Accumulated Depreciation |
2,183.9
|
|
2,115.1
|
|
|
|
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET |
$ 5,757.3
|
|
$ 5,316.2
|
|
|
|
Regulated Operation [Member] | Ohio Power Co [Member] | Maximum [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Depreciable Life Ranges - Transmission |
60 years
|
|
60 years
|
|
60 years
|
|
Depreciable Life Ranges - Distribution |
57 years
|
|
57 years
|
|
57 years
|
|
Depreciable Life Ranges - Other |
50 years
|
|
50 years
|
|
50 years
|
|
Regulated Operation [Member] | Ohio Power Co [Member] | Minimum [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Depreciable Life Ranges - Transmission |
39 years
|
|
39 years
|
|
39 years
|
|
Depreciable Life Ranges - Distribution |
5 years
|
|
7 years
|
|
7 years
|
|
Depreciable Life Ranges - Other |
5 years
|
|
5 years
|
|
5 years
|
|
Regulated Operation [Member] | Ohio Power Co [Member] | Transmission [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Annual Composite Depreciation Rate |
2.30%
|
|
2.30%
|
|
2.30%
|
|
Regulated Operation [Member] | Ohio Power Co [Member] | Distribution [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Annual Composite Depreciation Rate |
2.80%
|
|
2.80%
|
|
2.80%
|
|
Regulated Operation [Member] | Ohio Power Co [Member] | Other Property Class [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Annual Composite Depreciation Rate |
6.20%
|
|
5.90%
|
|
7.20%
|
|
Regulated Operation [Member] | Public Service Co Of Oklahoma [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Property, Plant and Equipment, Generation |
$ 1,577.2
|
|
$ 1,559.3
|
|
|
|
Property, Plant and Equipment, Transmission |
858.8
|
|
832.8
|
|
|
|
Property, Plant and Equipment, Distribution |
2,445.1
|
|
2,322.4
|
|
|
|
Property, Plant and Equipment, Other |
282.0
|
|
227.3
|
|
|
|
Property, Plant and Equipment, Construction Work in Progress |
111.3
|
|
148.2
|
|
|
|
Accumulated Depreciation |
1,393.6
|
|
1,272.7
|
|
|
|
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET |
$ 3,880.8
|
|
$ 3,817.3
|
|
|
|
Regulated Operation [Member] | Public Service Co Of Oklahoma [Member] | Maximum [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Depreciable Life Ranges - Generation |
85 years
|
|
85 years
|
|
70 years
|
|
Depreciable Life Ranges - Transmission |
100 years
|
|
100 years
|
|
75 years
|
|
Depreciable Life Ranges - Distribution |
156 years
|
|
156 years
|
|
65 years
|
|
Depreciable Life Ranges - Other |
84 years
|
|
84 years
|
|
40 years
|
|
Regulated Operation [Member] | Public Service Co Of Oklahoma [Member] | Minimum [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Depreciable Life Ranges - Generation |
35 years
|
|
35 years
|
|
35 years
|
|
Depreciable Life Ranges - Transmission |
45 years
|
|
45 years
|
|
40 years
|
|
Depreciable Life Ranges - Distribution |
27 years
|
|
27 years
|
|
7 years
|
|
Depreciable Life Ranges - Other |
5 years
|
|
5 years
|
|
5 years
|
|
Regulated Operation [Member] | Public Service Co Of Oklahoma [Member] | Generation [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Annual Composite Depreciation Rate |
2.40%
|
|
2.40%
|
|
1.70%
|
|
Regulated Operation [Member] | Public Service Co Of Oklahoma [Member] | Transmission [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Annual Composite Depreciation Rate |
2.20%
|
|
2.20%
|
|
1.90%
|
|
Regulated Operation [Member] | Public Service Co Of Oklahoma [Member] | Distribution [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Annual Composite Depreciation Rate |
2.70%
|
|
2.70%
|
|
2.50%
|
|
Regulated Operation [Member] | Public Service Co Of Oklahoma [Member] | Other Property Class [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Annual Composite Depreciation Rate |
7.40%
|
|
6.40%
|
|
4.60%
|
|
Regulated Operation [Member] | Southwestern Electric Power Co [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Property, Plant and Equipment, Generation |
$ 4,624.9
|
[21] |
$ 4,607.6
|
[21] |
|
|
Property, Plant and Equipment, Transmission |
1,679.8
|
|
1,584.2
|
|
|
|
Property, Plant and Equipment, Distribution |
2,095.8
|
|
2,020.6
|
|
|
|
Property, Plant and Equipment, Other |
416.8
|
|
399.3
|
|
|
|
Property, Plant and Equipment, Construction Work in Progress |
220.7
|
[21] |
113.7
|
[21] |
|
|
Accumulated Depreciation |
2,520.5
|
|
2,411.5
|
|
|
|
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET |
$ 6,517.5
|
|
$ 6,313.9
|
|
|
|
Regulated Operation [Member] | Southwestern Electric Power Co [Member] | Maximum [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Depreciable Life Ranges - Generation |
70 years
|
|
70 years
|
|
70 years
|
|
Depreciable Life Ranges - Transmission |
73 years
|
|
70 years
|
|
70 years
|
|
Depreciable Life Ranges - Distribution |
70 years
|
|
65 years
|
|
65 years
|
|
Depreciable Life Ranges - Other |
55 years
|
|
51 years
|
|
51 years
|
|
Regulated Operation [Member] | Southwestern Electric Power Co [Member] | Minimum [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Depreciable Life Ranges - Generation |
40 years
|
|
40 years
|
|
40 years
|
|
Depreciable Life Ranges - Transmission |
50 years
|
|
50 years
|
|
50 years
|
|
Depreciable Life Ranges - Distribution |
25 years
|
|
25 years
|
|
25 years
|
|
Depreciable Life Ranges - Other |
5 years
|
|
5 years
|
|
5 years
|
|
Regulated Operation [Member] | Southwestern Electric Power Co [Member] | Generation [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Annual Composite Depreciation Rate |
2.30%
|
|
2.10%
|
|
2.20%
|
|
Regulated Operation [Member] | Southwestern Electric Power Co [Member] | Transmission [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Annual Composite Depreciation Rate |
2.30%
|
|
2.20%
|
|
2.30%
|
|
Regulated Operation [Member] | Southwestern Electric Power Co [Member] | Distribution [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Annual Composite Depreciation Rate |
2.70%
|
|
2.60%
|
|
2.60%
|
|
Regulated Operation [Member] | Southwestern Electric Power Co [Member] | Other Property Class [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Annual Composite Depreciation Rate |
7.20%
|
|
6.80%
|
|
5.50%
|
|
Unregulated Operation [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET |
$ 756.1
|
|
$ 505.9
|
|
|
|
Unregulated Operation [Member] | Maximum [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Depreciable Life Ranges - Generation |
66 years
|
|
66 years
|
|
66 years
|
|
Depreciable Life Ranges - Transmission |
40 years
|
|
55 years
|
|
55 years
|
|
Depreciable Life Ranges - Distribution |
40 years
|
|
50 years
|
|
0 years
|
|
Depreciable Life Ranges - Other |
50 years
|
[22] |
50 years
|
[22] |
50 years
|
[22] |
Unregulated Operation [Member] | Minimum [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Depreciable Life Ranges - Generation |
15 years
|
|
40 years
|
|
35 years
|
|
Depreciable Life Ranges - Transmission |
|
|
43 years
|
|
43 years
|
|
Depreciable Life Ranges - Distribution |
|
|
40 years
|
|
0 years
|
|
Depreciable Life Ranges - Other |
5 years
|
[22] |
5 years
|
[22] |
5 years
|
[22] |
Unregulated Operation [Member] | Generation [Member] | Maximum [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Annual Composite Depreciation Rate |
5.10%
|
|
17.20%
|
|
3.40%
|
|
Unregulated Operation [Member] | Generation [Member] | Minimum [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Annual Composite Depreciation Rate |
2.40%
|
|
2.80%
|
|
2.50%
|
|
Unregulated Operation [Member] | Transmission [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Annual Composite Depreciation Rate |
0.20%
|
|
2.30%
|
|
2.30%
|
|
Unregulated Operation [Member] | Distribution [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Annual Composite Depreciation Rate |
2.30%
|
|
1.30%
|
|
0.00%
|
|
Unregulated Operation [Member] | Other Property Class [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Annual Composite Depreciation Rate |
12.10%
|
|
9.10%
|
|
2.70%
|
|
Unregulated Operation [Member] | AEP Texas Inc. [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET |
$ 160.3
|
|
$ 167.2
|
|
|
|
Unregulated Operation [Member] | AEP Transmission Co [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET |
1.4
|
|
1.1
|
|
|
|
Unregulated Operation [Member] | Appalachian Power Co [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET |
23.1
|
|
23.1
|
|
|
|
Unregulated Operation [Member] | Indiana Michigan Power Co [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET |
30.4
|
|
27.3
|
|
|
|
Unregulated Operation [Member] | Ohio Power Co [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET |
9.5
|
|
9.4
|
|
|
|
Unregulated Operation [Member] | Public Service Co Of Oklahoma [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET |
5.4
|
|
5.9
|
|
|
|
Unregulated Operation [Member] | Southwestern Electric Power Co [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET |
$ 114.5
|
|
115.6
|
|
|
|
Unregulated Operation [Member] | Southwestern Electric Power Co [Member] | Maximum [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Depreciable Life Ranges - Other |
20 years
|
|
|
|
|
|
Unregulated Operation [Member] | Southwestern Electric Power Co [Member] | Minimum [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Depreciable Life Ranges - Other |
3 years
|
|
|
|
|
|
Tanners Creek Plant Units 1 Through 4 [Member] |
|
|
|
|
|
|
Asset Retirement Obligations (ARO) |
|
|
|
|
|
|
Liabilities Settled |
|
|
61.0
|
|
|
|
Tanners Creek Plant Units 1 Through 4 [Member] | Indiana Michigan Power Co [Member] |
|
|
|
|
|
|
Asset Retirement Obligations (ARO) |
|
|
|
|
|
|
Liabilities Settled |
|
|
61.0
|
|
|
|
Generation and Marketing [Member] |
|
|
|
|
|
|
Depreciation, Depletion and Amortization |
|
|
|
|
|
|
Accumulated Depreciation |
$ 75.0
|
|
42.2
|
|
|
|
TOTAL PROPERTY, PLANT AND EQUIPMENT - NET |
569.6
|
|
322.5
|
|
|
|
Jointly-owned Electric Facilities |
|
|
|
|
|
|
Asset Impairments and Other Related Charges |
$ 53.5
|
|
2,257.3
|
|
|
|
Property, Plant and Equipment (Textuals) [Abstract] |
|
|
|
|
|
|
Property, Plant and Equipment -Assets Held for Sale |
|
|
$ 1,756.2
|
|
|
|
|
|