Guarantor Consolidating Financial Statements - Guarantor Cash Flow (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities
Net income	$ 1,085	$ 657	$ 485
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	6,706	4,789	2,365
Accretion and amortization of loan and leasing fees	(1,711)	(1,136)	(574)
Amortization of carrying value adjustment	0	(28)	(88)
Undistributed earnings of non-consolidated affiliate, net	(173)	(22)	(116)
Provision for loan losses (Note 4)	757	644	603
Deferred income taxes	42	8	128
Stock-based compensation expense	48	25	37
Other operating activities	(306)	(149)	(30)
Changes in assets and liabilities:
Other assets	(54)	(432)	(374)
Accounts payable and accrued expenses	153	209	251
Taxes payable	(29)	(5)	(10)
Related party taxes payable	0	0	(636)
Related party payables	1	1	6
Net cash provided by operating activities - continuing operations	6,519	4,561	2,047
Net cash provided by operating activities - discontinued operations	233	320	121
Net cash provided by operating activities	6,752	4,881	2,168
Cash flows from investing activities
Purchases of retail finance receivables, net	(19,524)	(14,180)	(13,905)
Principal collections and recoveries on retail finance receivables	12,854	9,899	8,548
Proceeds from transfer of retail finance receivables, net	0	0	0
Net funding of commercial finance receivables	(2,584)	(2,467)	(863)
Purchases of leased vehicles, net	(19,180)	(19,483)	(15,276)
Proceeds from termination of leased vehicles	6,667	2,554	1,095
Acquisition of equity interest	0	0	(1,049)
Disposition of equity interest	0	0	125
Purchases of property and equipment	(94)	(93)	(73)
Other investing activities	2	1	15
Net change in due from affiliates	0	0	0
Net change in investment in affiliates	0	0	0
Net cash used in investing activities - continuing operations	(21,859)	(23,769)	(21,383)
Net cash provided by (used in) investing activities - discontinued operations	3	(1,005)	(650)
Net cash used in investing activities	(21,856)	(24,774)	(22,033)
Cash flows from financing activities
Net change in debt (original maturities less than three months)	(105)	(309)	(21)
Borrowings and issuance of secured debt	32,480	27,379	19,203
Payments on secured debt	(27,451)	(17,294)	(11,503)
Borrowings and issuance of unsecured debt	15,883	12,234	12,043
Payments on unsecured debt	(5,018)	(2,754)	(1,652)
Borrowings on related party line of credit	0	418	0
Payments on related party line of credit	0	(418)	0
Proceeds from issuance of preferred stock	985	0	0
Dividends paid	(550)	0	0
Debt issuance costs	(155)	(131)	(134)
Net capital contributions	0	0	649
Other	0	0	1
Net change in due to affiliates	0	0	0
Net cash provided by financing activities - continuing operations	16,069	19,125	18,586
Net cash provided by financing activities - discontinued operations	219	1,109	1,531
Net cash provided by financing activities	16,288	20,234	20,117
Net increase in cash, cash equivalents and restricted cash	1,184	341	252
Effect of foreign exchange rate changes on cash, cash equivalents and restricted cash	81	(41)	(295)
Cash, cash equivalents and restricted cash at beginning of period	5,302	5,002	5,045
Cash, cash equivalents and restricted cash at end of period	6,567	5,302	5,002
Supplemental Cash Flow Elements
Cash and cash equivalents				$ 4,265	$ 2,815
Restricted cash included in other assets				2,302
Total	5,302	5,002	5,045	6,567	5,302
Continuing Operations [Member]
Cash flows from financing activities
Cash, cash equivalents and restricted cash at beginning of period	4,630	4,258
Cash, cash equivalents and restricted cash at end of period	6,567	4,630	4,258
Supplemental Cash Flow Elements
Cash and cash equivalents				4,265	2,815
Restricted cash included in other assets				2,302	1,815
Total	4,630	4,258	4,258	6,567	4,630
Discontinued Operations [Member]
Cash flows from financing activities
Cash, cash equivalents and restricted cash at beginning of period	672	744
Cash, cash equivalents and restricted cash at end of period	0	672	744
Supplemental Cash Flow Elements
Total	672	744	744	0	672
Eliminations [Member]
Cash flows from operating activities
Net income	(3,665)	(1,765)	(1,520)
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	0	0	0
Accretion and amortization of loan and leasing fees	0	0	0
Amortization of carrying value adjustment		0	0
Undistributed earnings of non-consolidated affiliate, net	3,665	1,765	1,520
Provision for loan losses (Note 4)	0	0	0
Deferred income taxes	0	0	0
Stock-based compensation expense	0	0	0
Other operating activities	0	0	0
Changes in assets and liabilities:
Other assets	0	0	0
Accounts payable and accrued expenses	0	0	0
Taxes payable	0	0	0
Related party taxes payable			0
Related party payables	0	0	0
Net cash provided by operating activities - continuing operations	0	0	0
Net cash provided by operating activities - discontinued operations	0	0	0
Net cash provided by operating activities	0	0	0
Cash flows from investing activities
Purchases of retail finance receivables, net	18,214	18,131	13,461
Principal collections and recoveries on retail finance receivables	0	0	0
Proceeds from transfer of retail finance receivables, net	(18,214)	(18,131)	(13,461)
Net funding of commercial finance receivables	0	0	0
Purchases of leased vehicles, net	0	0	0
Proceeds from termination of leased vehicles	0	0	0
Acquisition of equity interest			0
Disposition of equity interest			0
Purchases of property and equipment	0	0	0
Other investing activities	233	169	0
Net change in due from affiliates	17,302	17,474	15,357
Net change in investment in affiliates	(2,343)	(1,126)	1,851
Net cash used in investing activities - continuing operations	15,192	16,517	17,208
Net cash provided by (used in) investing activities - discontinued operations	0	0	(897)
Net cash used in investing activities	15,192	16,517	16,311
Cash flows from financing activities
Net change in debt (original maturities less than three months)	0	0	0
Borrowings and issuance of secured debt	(233)	(169)	0
Payments on secured debt	0	0	0
Borrowings and issuance of unsecured debt	0	0	0
Payments on unsecured debt	0	0	0
Borrowings on related party line of credit		0
Payments on related party line of credit		0
Proceeds from issuance of preferred stock	0
Dividends paid	0
Debt issuance costs	0	0	0
Net capital contributions	2,343	1,126	(1,851)
Other			0
Net change in due to affiliates	(17,302)	(17,474)	(15,357)
Net cash provided by financing activities - continuing operations	(15,192)	(16,517)	(17,208)
Net cash provided by financing activities - discontinued operations	0	0	897
Net cash provided by financing activities	(15,192)	(16,517)	(16,311)
Net increase in cash, cash equivalents and restricted cash	0	0	0
Effect of foreign exchange rate changes on cash, cash equivalents and restricted cash	0	0	0
Cash, cash equivalents and restricted cash at beginning of period	0	0	0
Cash, cash equivalents and restricted cash at end of period	0	0	0
Supplemental Cash Flow Elements
Cash and cash equivalents				0	0
Total	0	0	0	0	0
Eliminations [Member] | Continuing Operations [Member]
Cash flows from financing activities
Cash, cash equivalents and restricted cash at beginning of period	0	0
Cash, cash equivalents and restricted cash at end of period	0	0	0
Supplemental Cash Flow Elements
Cash and cash equivalents				0	0
Restricted cash included in other assets				0	0
Total	0	0	0	0	0
Eliminations [Member] | Discontinued Operations [Member]
Cash flows from financing activities
Cash, cash equivalents and restricted cash at beginning of period	0	0
Cash, cash equivalents and restricted cash at end of period	0	0	0
Supplemental Cash Flow Elements
Total	0	0	0	0	0
General Motors Financial Company, Inc. [Member]
Cash flows from operating activities
Net income	929	775	626
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	44	37	28
Accretion and amortization of loan and leasing fees	0	0	0
Amortization of carrying value adjustment		0	0
Undistributed earnings of non-consolidated affiliate, net	(2,050)	(994)	(941)
Provision for loan losses (Note 4)	0	0	0
Deferred income taxes	(80)	(334)	(169)
Stock-based compensation expense	39	24	33
Other operating activities	171	(299)	32
Changes in assets and liabilities:
Other assets	(5)	18	(3)
Accounts payable and accrued expenses	26	117	100
Taxes payable	(4)	(1)	(12)
Related party taxes payable			(636)
Related party payables	1	0	1
Net cash provided by operating activities - continuing operations	(929)	(657)	(941)
Net cash provided by operating activities - discontinued operations	26	0	0
Net cash provided by operating activities	(903)	(657)	(941)
Cash flows from investing activities
Purchases of retail finance receivables, net	0	0	0
Principal collections and recoveries on retail finance receivables	0	0	0
Proceeds from transfer of retail finance receivables, net	0	0	0
Net funding of commercial finance receivables	0	0	0
Purchases of leased vehicles, net	0	0	0
Proceeds from termination of leased vehicles	0	0	0
Acquisition of equity interest			(513)
Disposition of equity interest			0
Purchases of property and equipment	0	0	0
Other investing activities	0	0	0
Net change in due from affiliates	(10,764)	(8,966)	(9,764)
Net change in investment in affiliates	657	339	42
Net cash used in investing activities - continuing operations	(10,107)	(8,627)	(10,235)
Net cash provided by (used in) investing activities - discontinued operations	729	0	897
Net cash used in investing activities	(9,378)	(8,627)	(9,338)
Cash flows from financing activities
Net change in debt (original maturities less than three months)	129	8	0
Borrowings and issuance of secured debt	0	0	0
Payments on secured debt	0	0	0
Borrowings and issuance of unsecured debt	12,216	10,320	9,687
Payments on unsecured debt	(2,450)	(1,000)	0
Borrowings on related party line of credit		418
Payments on related party line of credit		(418)
Proceeds from issuance of preferred stock	985
Dividends paid	(550)
Debt issuance costs	(49)	(44)	(58)
Net capital contributions	0	0	649
Other			1
Net change in due to affiliates	0	0	0
Net cash provided by financing activities - continuing operations	10,281	9,284	10,279
Net cash provided by financing activities - discontinued operations	0	0	0
Net cash provided by financing activities	10,281	9,284	10,279
Net increase in cash, cash equivalents and restricted cash	0	0	0
Effect of foreign exchange rate changes on cash, cash equivalents and restricted cash	0	0	0
Cash, cash equivalents and restricted cash at beginning of period	0	0	0
Cash, cash equivalents and restricted cash at end of period	0	0	0
Supplemental Cash Flow Elements
Cash and cash equivalents				0	0
Total	0	0	0	0	0
General Motors Financial Company, Inc. [Member] | Continuing Operations [Member]
Cash flows from financing activities
Cash, cash equivalents and restricted cash at beginning of period	0	0
Cash, cash equivalents and restricted cash at end of period	0	0	0
Supplemental Cash Flow Elements
Cash and cash equivalents				0	0
Restricted cash included in other assets				0	0
Total	0	0	0	0	0
General Motors Financial Company, Inc. [Member] | Discontinued Operations [Member]
Cash flows from financing activities
Cash, cash equivalents and restricted cash at beginning of period	0	0
Cash, cash equivalents and restricted cash at end of period	0	0	0
Supplemental Cash Flow Elements
Total	0	0	0	0	0
Guarantor [Member]
Cash flows from operating activities
Net income	1,992	704	609
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	37	26	3
Accretion and amortization of loan and leasing fees	16	17	25
Amortization of carrying value adjustment		(3)	(14)
Undistributed earnings of non-consolidated affiliate, net	(1,615)	(771)	(579)
Provision for loan losses (Note 4)	430	378	398
Deferred income taxes	72	(390)	2
Stock-based compensation expense	0	0	0
Other operating activities	(281)	298	(5)
Changes in assets and liabilities:
Other assets	25	(347)	25
Accounts payable and accrued expenses	56	(438)	531
Taxes payable	0	0	1
Related party taxes payable			0
Related party payables	0	0	0
Net cash provided by operating activities - continuing operations	732	(526)	996
Net cash provided by operating activities - discontinued operations	(14)	(9)	0
Net cash provided by operating activities	718	(535)	996
Cash flows from investing activities
Purchases of retail finance receivables, net	(20,769)	(15,847)	(13,997)
Principal collections and recoveries on retail finance receivables	2,577	1,542	755
Proceeds from transfer of retail finance receivables, net	13,509	13,897	10,428
Net funding of commercial finance receivables	(302)	(191)	6
Purchases of leased vehicles, net	0	0	0
Proceeds from termination of leased vehicles	0	0	0
Acquisition of equity interest			(536)
Disposition of equity interest			125
Purchases of property and equipment	(77)	(82)	(21)
Other investing activities	(233)	(169)	0
Net change in due from affiliates	(6,538)	(8,508)	(5,593)
Net change in investment in affiliates	1,686	787	(1,893)
Net cash used in investing activities - continuing operations	(10,147)	(8,571)	(10,726)
Net cash provided by (used in) investing activities - discontinued operations	0	0	0
Net cash used in investing activities	(10,147)	(8,571)	(10,726)
Cash flows from financing activities
Net change in debt (original maturities less than three months)	0	0	0
Borrowings and issuance of secured debt	0	0	0
Payments on secured debt	0	0	0
Borrowings and issuance of unsecured debt	0	0	0
Payments on unsecured debt	0	0	0
Borrowings on related party line of credit		0
Payments on related party line of credit		0
Proceeds from issuance of preferred stock	0
Dividends paid	0
Debt issuance costs	0	0	0
Net capital contributions	0	0	0
Other			0
Net change in due to affiliates	10,680	9,071	9,751
Net cash provided by financing activities - continuing operations	10,680	9,071	9,751
Net cash provided by financing activities - discontinued operations	0	0	15
Net cash provided by financing activities	10,680	9,071	9,766
Net increase in cash, cash equivalents and restricted cash	1,251	(35)	36
Effect of foreign exchange rate changes on cash, cash equivalents and restricted cash	0	0	0
Cash, cash equivalents and restricted cash at beginning of period	2,284	2,319	2,283
Cash, cash equivalents and restricted cash at end of period	3,535	2,284	2,319
Supplemental Cash Flow Elements
Cash and cash equivalents				3,535	2,284
Total	2,284	2,319	2,283	3,535	2,284
Guarantor [Member] | Continuing Operations [Member]
Cash flows from financing activities
Cash, cash equivalents and restricted cash at beginning of period	2,284	2,319
Cash, cash equivalents and restricted cash at end of period	3,535	2,284	2,319
Supplemental Cash Flow Elements
Cash and cash equivalents				3,535	2,284
Restricted cash included in other assets				0	0
Total	2,284	2,319	2,319	3,535	2,284
Guarantor [Member] | Discontinued Operations [Member]
Cash flows from financing activities
Cash, cash equivalents and restricted cash at beginning of period	0	0
Cash, cash equivalents and restricted cash at end of period	0	0	0
Supplemental Cash Flow Elements
Total	0	0	0	0	0
Non-Guarantors [Member]
Cash flows from operating activities
Net income	1,829	943	770
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	6,625	4,726	2,334
Accretion and amortization of loan and leasing fees	(1,727)	(1,153)	(599)
Amortization of carrying value adjustment		(25)	(74)
Undistributed earnings of non-consolidated affiliate, net	(173)	(22)	(116)
Provision for loan losses (Note 4)	327	266	205
Deferred income taxes	50	732	295
Stock-based compensation expense	9	1	4
Other operating activities	(196)	(148)	(57)
Changes in assets and liabilities:
Other assets	(74)	(103)	(396)
Accounts payable and accrued expenses	71	530	(380)
Taxes payable	(25)	(4)	1
Related party taxes payable			0
Related party payables	0	1	5
Net cash provided by operating activities - continuing operations	6,716	5,744	1,992
Net cash provided by operating activities - discontinued operations	221	329	121
Net cash provided by operating activities	6,937	6,073	2,113
Cash flows from investing activities
Purchases of retail finance receivables, net	(16,969)	(16,464)	(13,369)
Principal collections and recoveries on retail finance receivables	10,277	8,357	7,793
Proceeds from transfer of retail finance receivables, net	4,705	4,234	3,033
Net funding of commercial finance receivables	(2,282)	(2,276)	(869)
Purchases of leased vehicles, net	(19,180)	(19,483)	(15,276)
Proceeds from termination of leased vehicles	6,667	2,554	1,095
Acquisition of equity interest			0
Disposition of equity interest			0
Purchases of property and equipment	(17)	(11)	(52)
Other investing activities	2	1	15
Net change in due from affiliates	0	0	0
Net change in investment in affiliates	0	0	0
Net cash used in investing activities - continuing operations	(16,797)	(23,088)	(17,630)
Net cash provided by (used in) investing activities - discontinued operations	(726)	(1,005)	(650)
Net cash used in investing activities	(17,523)	(24,093)	(18,280)
Cash flows from financing activities
Net change in debt (original maturities less than three months)	(234)	(317)	(21)
Borrowings and issuance of secured debt	32,713	27,548	19,203
Payments on secured debt	(27,451)	(17,294)	(11,503)
Borrowings and issuance of unsecured debt	3,667	1,914	2,356
Payments on unsecured debt	(2,568)	(1,754)	(1,652)
Borrowings on related party line of credit		0
Payments on related party line of credit		0
Proceeds from issuance of preferred stock	0
Dividends paid	0
Debt issuance costs	(106)	(87)	(76)
Net capital contributions	(2,343)	(1,126)	1,851
Other			0
Net change in due to affiliates	6,622	8,403	5,606
Net cash provided by financing activities - continuing operations	10,300	17,287	15,764
Net cash provided by financing activities - discontinued operations	219	1,109	619
Net cash provided by financing activities	10,519	18,396	16,383
Net increase in cash, cash equivalents and restricted cash	(67)	376	216
Effect of foreign exchange rate changes on cash, cash equivalents and restricted cash	81	(41)	(295)
Cash, cash equivalents and restricted cash at beginning of period	3,018	2,683	2,762
Cash, cash equivalents and restricted cash at end of period	3,032	3,018	2,683
Supplemental Cash Flow Elements
Cash and cash equivalents				730	531
Total	3,018	2,683	2,762	3,032	3,018
Non-Guarantors [Member] | Continuing Operations [Member]
Cash flows from financing activities
Cash, cash equivalents and restricted cash at beginning of period	2,346	1,939
Cash, cash equivalents and restricted cash at end of period	3,032	2,346	1,939
Supplemental Cash Flow Elements
Cash and cash equivalents				730	531
Restricted cash included in other assets					1,815
Total	2,346	1,939	1,939	3,032	2,346
Non-Guarantors [Member] | Discontinued Operations [Member]
Cash flows from financing activities
Cash, cash equivalents and restricted cash at beginning of period	672	744
Cash, cash equivalents and restricted cash at end of period	0	672	744
Supplemental Cash Flow Elements
Total	$ 672	$ 744	$ 744	$ 0	$ 672