REVENUE FROM CONTRACTS WITH CUSTOMERS - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	$ 5,962.1	$ 5,470.1	$ 16,432.6	$ 15,212.7
Total Revenues	6,010.4	5,420.1	16,560.7	15,025.0
Related Party
Disaggregation of Revenue [Line Items]
Total Revenues	0.0	0.0	0.0	0.0
Retail Revenues:
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	4,443.8	4,202.9	12,128.1	11,498.6
Residential Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	2,233.6	2,136.6	5,966.4	5,651.9
Commercial Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	1,284.4	1,172.6	3,501.4	3,255.6
Industrial Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	843.4	816.0	2,433.5	2,374.7
Other Retail Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	82.4	77.7	226.8	216.4
Wholesale and Competitive Retail Revenues:
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	1,342.4	1,141.3	3,922.4	3,376.5
Generation Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	310.1	228.0	941.7	664.0
Transmission Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	403.1	390.8	1,223.0	1,190.5
Renewable Generation Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.1	7.2	0.1	18.9
Retail, Trading and Marketing Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	629.1	515.3	1,757.6	1,503.1
Other Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	175.9	125.9	382.1	337.6
Total Revenues	125.2	119.1	415.8	380.4
Alternative and Other
Disaggregation of Revenue [Line Items]
Total Other Revenues	48.3	(50.0)	128.1	(187.7)
Alternative Revenue Programs
Disaggregation of Revenue [Line Items]
Total Other Revenues	24.0	12.8	56.7	(21.3)
Other Revenues
Disaggregation of Revenue [Line Items]
Total Other Revenues	24.3	(62.8)	71.4	(166.4)
AEP Texas
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	615.1	572.7	1,670.6	1,579.3
Total Revenues	619.1	571.2	1,673.3	1,577.2
AEP Texas | Retail Revenues:
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	420.4	393.9	1,108.6	1,040.6
AEP Texas | Residential Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	243.6	230.2	595.7	562.4
AEP Texas | Commercial Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	123.9	120.3	357.8	346.2
AEP Texas | Industrial Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	41.6	33.7	122.8	103.3
AEP Texas | Other Retail Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	11.3	9.7	32.3	28.7
AEP Texas | Wholesale and Competitive Retail Revenues:
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	184.3	170.6	533.0	511.3
AEP Texas | Generation Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.0	0.0	0.0
AEP Texas | Transmission Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	184.3	170.6	533.0	511.3
AEP Texas | Other Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	10.4	8.2	29.0	27.4
Total Revenues	2.2	0.7	5.4	3.3
AEP Texas | Alternative and Other
Disaggregation of Revenue [Line Items]
Total Other Revenues	4.0	(1.5)	2.7	(2.1)
AEP Texas | Alternative Revenue Programs
Disaggregation of Revenue [Line Items]
Total Other Revenues	3.8	(1.5)	2.7	(2.1)
AEP Texas | Other Revenues
Disaggregation of Revenue [Line Items]
Total Other Revenues	0.2	0.0	0.0	0.0
AEPTCo
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	527.9	497.9	1,733.9	1,470.8
Total Revenues	558.0	497.2	1,826.9	1,455.2
AEPTCo | Retail Revenues:
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.0	0.0	0.0
AEPTCo | Residential Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.0	0.0	0.0
AEPTCo | Commercial Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.0	0.0	0.0
AEPTCo | Industrial Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.0	0.0	0.0
AEPTCo | Other Retail Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.0	0.0	0.0
AEPTCo | Wholesale and Competitive Retail Revenues:
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	515.9	491.9	1,704.1	1,450.5
AEPTCo | Generation Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.0	0.0	0.0
AEPTCo | Transmission Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	515.9	491.9	1,704.1	1,450.5
AEPTCo | Transmission Revenues | Related Party
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	419.0	399.0	1,400.0	1,200.0
AEPTCo | Other Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	12.0	6.0	29.8	20.3
Total Revenues	0.0	0.2	0.1	3.0
AEPTCo | Alternative and Other
Disaggregation of Revenue [Line Items]
Total Other Revenues	30.1	(0.7)	93.0	(15.6)
AEPTCo | Alternative Revenue Programs
Disaggregation of Revenue [Line Items]
Total Other Revenues	30.1	(0.7)	93.0	(15.6)
AEPTCo | Other Revenues
Disaggregation of Revenue [Line Items]
Total Other Revenues	0.0	0.0	0.0	0.0
APCo
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	1,049.4	1,028.8	3,155.9	3,038.5
Total Revenues	1,056.0	1,028.9	3,176.5	3,032.1
APCo | Retail Revenues:
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	856.7	868.3	2,675.1	2,593.3
APCo | Residential Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	438.2	442.6	1,409.8	1,333.7
APCo | Commercial Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	194.0	196.4	582.5	571.8
APCo | Industrial Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	197.7	201.2	599.6	603.5
APCo | Other Retail Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	26.8	28.1	83.2	84.3
APCo | Wholesale and Competitive Retail Revenues:
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	150.5	124.3	405.7	374.2
APCo | Generation Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	106.1	78.7	273.6	235.9
APCo | Generation Revenues | Related Party
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	41.0	41.0	122.0	118.0
APCo | Transmission Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	44.4	45.6	132.1	138.3
APCo | Transmission Revenues | Related Party
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	19.0	22.0	60.0	65.0
APCo | Other Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	42.2	36.2	75.1	71.0
Total Revenues	4.0	3.1	12.6	12.4
APCo | Alternative and Other
Disaggregation of Revenue [Line Items]
Total Other Revenues	6.6	0.1	20.6	(6.4)
APCo | Alternative Revenue Programs
Disaggregation of Revenue [Line Items]
Total Other Revenues	6.5	0.0	20.2	(6.6)
APCo | Other Revenues
Disaggregation of Revenue [Line Items]
Total Other Revenues	0.1	0.1	0.4	0.2
I&M
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	805.3	735.1	2,284.3	2,018.8
Total Revenues	812.2	733.5	2,271.6	1,995.2
I&M | Retail Revenues:
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	617.2	575.9	1,677.0	1,590.4
I&M | Residential Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	249.1	249.4	671.3	664.7
I&M | Commercial Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	216.8	169.9	561.5	465.5
I&M | Industrial Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	150.1	155.4	440.5	456.4
I&M | Other Retail Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	1.2	1.2	3.7	3.8
I&M | Wholesale and Competitive Retail Revenues:
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	152.2	123.9	514.5	336.1
I&M | Generation Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	141.1	113.5	474.4	305.6
I&M | Transmission Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	11.1	10.4	40.1	30.5
I&M | Other Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	35.9	35.3	92.8	92.3
I&M | Other Revenues | Related Party
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	19.0	18.0	55.0	59.0
I&M | Alternative and Other
Disaggregation of Revenue [Line Items]
Total Other Revenues	6.9	(1.6)	(12.7)	(23.6)
I&M | Alternative Revenue Programs
Disaggregation of Revenue [Line Items]
Total Other Revenues	0.9	(0.4)	1.9	(0.9)
I&M | Other Revenues
Disaggregation of Revenue [Line Items]
Total Other Revenues	6.0	(1.2)	(14.6)	(22.7)
OPCo
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	1,048.8	989.0	2,946.9	2,889.3
Total Revenues	1,070.2	1,004.2	2,992.7	2,924.3
OPCo | Retail Revenues:
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	949.1	913.7	2,711.9	2,695.9
OPCo | Residential Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	554.2	543.4	1,552.9	1,565.2
OPCo | Commercial Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	298.8	276.2	867.3	838.4
OPCo | Industrial Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	92.1	89.9	279.1	279.4
OPCo | Other Retail Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	4.0	4.2	12.6	12.9
OPCo | Wholesale and Competitive Retail Revenues:
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	25.7	24.5	71.4	71.9
OPCo | Generation Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.0	0.0	0.0
OPCo | Transmission Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	25.7	24.5	71.4	71.9
OPCo | Other Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	74.0	50.8	163.6	121.5
Total Revenues	3.6	2.8	9.8	8.3
OPCo | Alternative and Other
Disaggregation of Revenue [Line Items]
Total Other Revenues	21.4	15.2	45.8	35.0
OPCo | Alternative Revenue Programs
Disaggregation of Revenue [Line Items]
Total Other Revenues	13.6	11.9	30.7	19.8
OPCo | Other Revenues
Disaggregation of Revenue [Line Items]
Total Other Revenues	7.8	3.3	15.1	15.2
PSO
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	693.0	615.6	1,554.6	1,463.8
Total Revenues	693.4	615.4	1,556.9	1,462.0
PSO | Retail Revenues:
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	665.1	595.5	1,476.2	1,393.4
PSO | Residential Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	334.9	301.1	700.6	647.1
PSO | Commercial Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	184.4	165.1	421.5	398.2
PSO | Industrial Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	112.1	98.5	273.8	269.9
PSO | Other Retail Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	33.7	30.8	80.3	78.2
PSO | Wholesale and Competitive Retail Revenues:
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	14.2	14.1	49.6	40.0
PSO | Generation Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	6.1	2.1	11.7	7.0
PSO | Transmission Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	8.1	12.0	37.9	33.0
PSO | Other Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	13.7	6.0	28.8	30.4
Total Revenues	4.4	1.4	9.5	17.2
PSO | Alternative and Other
Disaggregation of Revenue [Line Items]
Total Other Revenues	0.4	(0.2)	2.3	(1.8)
PSO | Alternative Revenue Programs
Disaggregation of Revenue [Line Items]
Total Other Revenues	0.3	(0.2)	2.2	(1.8)
PSO | Other Revenues
Disaggregation of Revenue [Line Items]
Total Other Revenues	0.1	0.0	0.1	0.0
SWEPCo
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	721.5	638.9	1,814.2	1,555.0
Total Revenues	723.9	638.8	1,825.4	1,550.8
SWEPCo | Retail Revenues:
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	601.6	537.4	1,479.9	1,252.8
SWEPCo | Residential Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	296.8	260.1	680.7	563.2
SWEPCo | Commercial Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	189.0	172.5	485.1	413.2
SWEPCo | Industrial Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	112.3	102.5	305.2	269.8
SWEPCo | Other Retail Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	3.5	2.3	8.9	6.6
SWEPCo | Wholesale and Competitive Retail Revenues:
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	104.1	92.7	302.7	276.2
SWEPCo | Generation Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	43.2	42.7	147.5	139.9
SWEPCo | Transmission Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	60.9	50.0	155.2	136.3
SWEPCo | Transmission Revenues | Related Party
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	28.0	22.0	59.0	50.0
SWEPCo | Other Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	15.8	8.8	31.6	26.0
Total Revenues	6.0	0.7	10.1	7.0
SWEPCo | Alternative and Other
Disaggregation of Revenue [Line Items]
Total Other Revenues	2.4	(0.1)	11.2	(4.2)
SWEPCo | Alternative Revenue Programs
Disaggregation of Revenue [Line Items]
Total Other Revenues	2.4	(0.1)	11.2	(4.2)
SWEPCo | Other Revenues
Disaggregation of Revenue [Line Items]
Total Other Revenues	0.0	0.0	0.0	0.0
Operating Segments
Disaggregation of Revenue [Line Items]
Total Revenues	6,560.9	5,890.0	18,302.4	16,401.2
Operating Segments | Related Party
Disaggregation of Revenue [Line Items]
Total Revenues	556.0	475.9	1,766.8	1,424.3
Corporate and Other
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	34.1	37.4	104.5	153.8
Total Revenues	35.9	38.1	110.1	148.6
Corporate and Other | Related Party
Disaggregation of Revenue [Line Items]
Total Revenues	30.4	32.1	85.0	100.5
Corporate and Other | Retail Revenues:
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.0	0.0	0.0
Corporate and Other | Residential Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.0	0.0	0.0
Corporate and Other | Commercial Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.0	0.0	0.0
Corporate and Other | Industrial Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.0	0.0	0.0
Corporate and Other | Other Retail Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.0	0.0	0.0
Corporate and Other | Wholesale and Competitive Retail Revenues:
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	(0.2)	(0.2)	0.6
Corporate and Other | Generation Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.0	0.0	0.0
Corporate and Other | Transmission Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.0	0.0	0.0
Corporate and Other | Renewable Generation Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.0	0.0	0.0
Corporate and Other | Retail, Trading and Marketing Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	(0.2)	(0.2)	0.6
Corporate and Other | Other Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	34.1	37.6	104.7	153.2
Corporate and Other | Other Revenues | Related Party
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	31.0	34.0	86.0	112.0
Corporate and Other | Alternative and Other
Disaggregation of Revenue [Line Items]
Total Other Revenues	1.8	0.7	5.6	(5.2)
Corporate and Other | Alternative Revenue Programs
Disaggregation of Revenue [Line Items]
Total Other Revenues	0.0	0.0	0.0	0.0
Corporate and Other | Other Revenues
Disaggregation of Revenue [Line Items]
Total Other Revenues	1.8	0.7	5.6	(5.2)
Corporate and Other | AEPTCo
Disaggregation of Revenue [Line Items]
Total Revenues	0.0	0.0	0.0	0.0
Reconciling Adjustments
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	(552.2)	(508.3)	(1,751.1)	(1,514.4)
Total Revenues	(586.4)	(508.0)	(1,851.8)	(1,524.8)
Reconciling Adjustments | Related Party
Disaggregation of Revenue [Line Items]
Total Revenues	(586.4)	(508.0)	(1,851.8)	(1,524.8)
Reconciling Adjustments | Retail Revenues:
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	(0.1)	(0.3)	(0.6)	(0.6)
Reconciling Adjustments | Residential Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.0	0.0	0.0
Reconciling Adjustments | Commercial Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.0	0.0	0.0
Reconciling Adjustments | Industrial Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	(0.1)	(0.3)	(0.6)	(0.6)
Reconciling Adjustments | Other Retail Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.0	0.0	0.0
Reconciling Adjustments | Wholesale and Competitive Retail Revenues:
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	(498.4)	(454.6)	(1,602.2)	(1,342.9)
Reconciling Adjustments | Generation Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.1	0.0	0.1
Reconciling Adjustments | Transmission Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	(479.5)	(439.4)	(1,551.8)	(1,255.0)
Reconciling Adjustments | Renewable Generation Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	(1.5)	0.0	(4.3)
Reconciling Adjustments | Retail, Trading and Marketing Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	(18.9)	(13.8)	(50.4)	(83.7)
Reconciling Adjustments | Other Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	(53.7)	(53.4)	(148.3)	(170.9)
Reconciling Adjustments | Alternative and Other
Disaggregation of Revenue [Line Items]
Total Other Revenues	(34.2)	0.3	(100.7)	(10.4)
Reconciling Adjustments | Alternative Revenue Programs
Disaggregation of Revenue [Line Items]
Total Other Revenues	(32.0)	1.0	(94.3)	(15.3)
Reconciling Adjustments | Other Revenues
Disaggregation of Revenue [Line Items]
Total Other Revenues	(2.2)	(0.7)	(6.4)	4.9
Reconciling Adjustments | AEPTCo
Disaggregation of Revenue [Line Items]
Total Revenues	0.0	0.0	0.0	0.0
VIU | Transmission Revenues | Related Party
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	56.0	51.0	160.0	133.0
VIU | Operating Segments
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	3,571.3	3,303.7	9,726.7	8,904.8
Total Revenues	3,585.7	3,303.0	9,738.7	8,869.9
VIU | Operating Segments | Related Party
Disaggregation of Revenue [Line Items]
Total Revenues	74.5	54.2	207.5	147.9
VIU | Operating Segments | Retail Revenues:
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	3,074.3	2,895.4	8,308.3	7,762.6
VIU | Operating Segments | Residential Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	1,435.8	1,362.9	3,817.8	3,524.2
VIU | Operating Segments | Commercial Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	861.7	776.1	2,276.4	2,071.0
VIU | Operating Segments | Industrial Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	709.8	692.6	2,032.2	1,992.5
VIU | Operating Segments | Other Retail Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	67.0	63.8	181.9	174.9
VIU | Operating Segments | Wholesale and Competitive Retail Revenues:
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	400.9	332.1	1,221.3	958.9
VIU | Operating Segments | Generation Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	259.6	202.5	801.9	587.4
VIU | Operating Segments | Transmission Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	141.3	129.6	419.4	371.5
VIU | Operating Segments | Renewable Generation Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.0	0.0	0.0
VIU | Operating Segments | Retail, Trading and Marketing Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.0	0.0	0.0
VIU | Operating Segments | Other Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	96.1	76.2	197.1	183.3
VIU | Operating Segments | Alternative and Other
Disaggregation of Revenue [Line Items]
Total Other Revenues	14.4	(0.7)	12.0	(34.9)
VIU | Operating Segments | Alternative Revenue Programs
Disaggregation of Revenue [Line Items]
Total Other Revenues	8.6	0.3	26.4	(12.5)
VIU | Operating Segments | Other Revenues
Disaggregation of Revenue [Line Items]
Total Other Revenues	5.8	(1.0)	(14.4)	(22.4)
T&D | Operating Segments
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	1,664.0	1,561.8	4,617.3	4,468.6
Total Revenues	1,689.3	1,575.4	4,666.0	4,501.5
T&D | Operating Segments | Related Party
Disaggregation of Revenue [Line Items]
Total Revenues	9.1	6.9	27.7	21.0
T&D | Operating Segments | Retail Revenues:
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	1,369.6	1,307.8	3,820.4	3,736.6
T&D | Operating Segments | Residential Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	797.8	773.7	2,148.6	2,127.7
T&D | Operating Segments | Commercial Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	422.7	396.5	1,225.0	1,184.6
T&D | Operating Segments | Industrial Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	133.7	123.7	401.9	382.8
T&D | Operating Segments | Other Retail Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	15.4	13.9	44.9	41.5
T&D | Operating Segments | Wholesale and Competitive Retail Revenues:
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	210.0	195.1	604.4	583.2
T&D | Operating Segments | Generation Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.0	0.0	0.0
T&D | Operating Segments | Transmission Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	210.0	195.1	604.4	583.2
T&D | Operating Segments | Renewable Generation Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.0	0.0	0.0
T&D | Operating Segments | Retail, Trading and Marketing Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.0	0.0	0.0
T&D | Operating Segments | Other Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	84.4	58.9	192.5	148.8
T&D | Operating Segments | Alternative and Other
Disaggregation of Revenue [Line Items]
Total Other Revenues	25.3	13.6	48.7	32.9
T&D | Operating Segments | Alternative Revenue Programs
Disaggregation of Revenue [Line Items]
Total Other Revenues	17.6	10.3	33.5	17.7
T&D | Operating Segments | Other Revenues
Disaggregation of Revenue [Line Items]
Total Other Revenues	7.7	3.3	15.2	15.2
AEPTHCo | Transmission Revenues | Related Party
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	423.0	402.0	1,400.0	1,200.0
AEPTHCo | Alternative Revenue Programs | Related Party
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	25.0		74.0
AEPTHCo | Operating Segments
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	543.3	511.3	1,780.7	1,510.9
Total Revenues	573.2	512.5	1,871.9	1,499.7
AEPTHCo | Operating Segments | Retail Revenues:
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.0	0.0	0.0
AEPTHCo | Operating Segments | Residential Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.0	0.0	0.0
AEPTHCo | Operating Segments | Commercial Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.0	0.0	0.0
AEPTHCo | Operating Segments | Industrial Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.0	0.0	0.0
AEPTHCo | Operating Segments | Other Retail Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.0	0.0	0.0
AEPTHCo | Operating Segments | Wholesale and Competitive Retail Revenues:
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	531.3	505.5	1,751.0	1,490.8
AEPTHCo | Operating Segments | Generation Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.0	0.0	0.0
AEPTHCo | Operating Segments | Transmission Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	531.3	505.5	1,751.0	1,490.8
AEPTHCo | Operating Segments | Renewable Generation Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.0	0.0	0.0
AEPTHCo | Operating Segments | Retail, Trading and Marketing Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.0	0.0	0.0
AEPTHCo | Operating Segments | Other Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	12.0	5.8	29.7	20.1
AEPTHCo | Operating Segments | Alternative and Other
Disaggregation of Revenue [Line Items]
Total Other Revenues	29.9	1.2	91.2	(11.2)
AEPTHCo | Operating Segments | Alternative Revenue Programs
Disaggregation of Revenue [Line Items]
Total Other Revenues	29.8	1.2	91.1	(11.2)
AEPTHCo | Operating Segments | Other Revenues
Disaggregation of Revenue [Line Items]
Total Other Revenues	0.1	0.0	0.1	0.0
G&M | Retail, Trading and Marketing Revenues | Related Party
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	18.0	14.0	50.0	84.0
G&M | Operating Segments
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	701.6	564.2	1,954.5	1,689.0
Total Revenues	712.7	499.1	2,025.8	1,530.1
G&M | Operating Segments | Related Party
Disaggregation of Revenue [Line Items]
Total Revenues	18.9	15.4	50.4	88.0
G&M | Operating Segments | Retail Revenues:
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.0	0.0	0.0
G&M | Operating Segments | Residential Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.0	0.0	0.0
G&M | Operating Segments | Commercial Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.0	0.0	0.0
G&M | Operating Segments | Industrial Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.0	0.0	0.0
G&M | Operating Segments | Other Retail Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.0	0.0	0.0
G&M | Operating Segments | Wholesale and Competitive Retail Revenues:
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	698.6	563.4	1,948.1	1,685.9
G&M | Operating Segments | Generation Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	50.5	25.4	139.8	76.5
G&M | Operating Segments | Transmission Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.0	0.0	0.0	0.0
G&M | Operating Segments | Renewable Generation Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	0.1	8.7	0.1	23.2
G&M | Operating Segments | Retail, Trading and Marketing Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	648.0	529.3	1,808.2	1,586.2
G&M | Operating Segments | Other Revenues
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	3.0	0.8	6.4	3.1
G&M | Operating Segments | Alternative and Other
Disaggregation of Revenue [Line Items]
Total Other Revenues	11.1	(65.1)	71.3	(158.9)
G&M | Operating Segments | Alternative Revenue Programs
Disaggregation of Revenue [Line Items]
Total Other Revenues	0.0	0.0	0.0	0.0
G&M | Operating Segments | Other Revenues
Disaggregation of Revenue [Line Items]
Total Other Revenues	11.1	$ (65.1)	71.3	$ (158.9)
AEPTCo | Alternative Revenue Programs | Related Party
Disaggregation of Revenue [Line Items]
Total Revenues from Contracts with Customers	$ 25.0		$ 73.0