Derivative Financial Instruments and Hedging Activities - Schedule of Income (Losses) Recognized in Income (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Derivatives, Fair Value [Line Items]
Interest expense	$ 1,638	$ 1,485	$ 3,235	$ 2,881
Operating expenses	523	479	1,035	937
Gains to be reclassified in next twelve months			61
AOCI Attributable to Parent
Derivatives, Fair Value [Line Items]
Gains (Losses) Recognized In Accumulated Other Comprehensive Income (Loss)	478	(57)	621	(189)
(Gains) Losses Reclassified From Accumulated Other Comprehensive Income (Loss) Into Income (Loss)	(483)	48	(717)	206
Interest Expense
Derivatives, Fair Value [Line Items]
Total income (loss) recognized	(86)	(56)	(179)	(84)
Operating Expense
Derivatives, Fair Value [Line Items]
Total income (loss) recognized	0	(2)	(1)	1
Interest rate swaps \| Fair value hedges \| Derivatives designated as hedges \| Interest Expense
Derivatives, Fair Value [Line Items]
Hedged items	(200)	62	(521)	192
Interest rate swaps and Foreign currency swaps	149	(130)	400	(287)
Interest rate swaps \| Fair value hedges \| Derivatives designated as hedges \| Operating Expense
Derivatives, Fair Value [Line Items]
Hedged items	0	0	0	0
Interest rate swaps and Foreign currency swaps	0	0	0	0
Interest rate swaps \| Cash flow hedges \| Unrealized gain (loss) on hedges
Derivatives, Fair Value [Line Items]
Gains (Losses) Recognized In Accumulated Other Comprehensive Income (Loss)	(10)	17	(24)	26
(Gains) Losses Reclassified From Accumulated Other Comprehensive Income (Loss) Into Income (Loss)	(4)	(2)	(6)	(7)
Interest rate swaps \| Cash flow hedges \| Derivatives designated as hedges \| Interest Expense
Derivatives, Fair Value [Line Items]
Interest rate swaps and Foreign currency swaps	4	4	8	11
Interest rate swaps \| Cash flow hedges \| Derivatives designated as hedges \| Operating Expense
Derivatives, Fair Value [Line Items]
Interest rate swaps and Foreign currency swaps	0	0	0	0
Foreign currency swaps \| Cash flow hedges \| Foreign currency translation adjustment
Derivatives, Fair Value [Line Items]
Gains (Losses) Recognized In Accumulated Other Comprehensive Income (Loss)	489	(74)	645	(215)
(Gains) Losses Reclassified From Accumulated Other Comprehensive Income (Loss) Into Income (Loss)	(480)	49	(711)	212
Foreign currency swaps \| Cash flow hedges \| Derivatives designated as hedges \| Interest Expense
Derivatives, Fair Value [Line Items]
Hedged items	0	0	0	0
Interest rate swaps and Foreign currency swaps	(18)	(34)	(52)	(75)
Foreign currency swaps \| Cash flow hedges \| Derivatives designated as hedges \| Operating Expense
Derivatives, Fair Value [Line Items]
Hedged items	(652)	30	(992)	208
Interest rate swaps and Foreign currency swaps	652	(30)	992	(206)
Interest rate contracts \| Derivatives not designated as hedges \| Interest Expense
Derivatives, Fair Value [Line Items]
Interest rate contracts	(22)	42	(14)	75
Interest rate contracts \| Derivatives not designated as hedges \| Operating Expense
Derivatives, Fair Value [Line Items]
Interest rate contracts	0	0	0	0
Foreign currency contracts \| Derivatives not designated as hedges \| Interest Expense
Derivatives, Fair Value [Line Items]
Foreign currency contracts	0	0	0	0
Foreign currency contracts \| Derivatives not designated as hedges \| Operating Expense
Derivatives, Fair Value [Line Items]
Foreign currency contracts	$ 0	$ (2)	$ 0	$ 0

General Motors Financial Company, Inc. 10-Q