Guarantor Consolidating Financial Statements - Current Period Guarantor Balance Sheet (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	$ 2,974	$ 1,074	$ 1,289	$ 572
Finance receivables, net (Note 4) ($23,109 and $21,781 in VIEs; Note 8)	33,000	29,282
Leased vehicles, net (Note 6) ($4,595 and $1,803 in VIEs; Note 8)	7,060	3,383
Restricted cash (Note 5)	2,071	1,958
Goodwill (Note 3)	1,244	1,240	1,108
Property and equipment, net of accumulated depreciation of $59 and $38	172	132
Deferred income taxes (Note 14)	341	359
Related party receivables	384	129
Other assets	478	433
Due from Affiliates	0	0
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	0	0
Total assets	47,724	37,990
Secured debt	25,214	22,073
Unsecured debt	12,217	6,973
Accounts payable and accrued expenses	1,002	946
Deferred income	392	168
Deferred income taxes (Note 14)	20	87
Taxes payable	234	287
Related party taxes payable	636	643
Related party payables	433	368
Derivative Liability	184	160
Due to Affiliate	0	0
Total liabilities	40,332	31,705
Common stock, $1.00 par value per share, 1,000 shares authorized and 505 and 502 shares issued	0	0
Additional Paid in Capital, Common Stock	5,799	4,785
Accumulated other comprehensive (loss) income (Note 18)	(433)	11	(3)
Retained Earnings (Accumulated Deficit)	2,026	1,489
Total stockholders' equity	7,392	6,285
Total liabilities and shareholder's equity	47,724	37,990
Parent Company [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	0	0	0	0
Finance receivables, net (Note 4) ($23,109 and $21,781 in VIEs; Note 8)	0	0
Leased vehicles, net (Note 6) ($4,595 and $1,803 in VIEs; Note 8)	0	0
Restricted cash (Note 5)	0	0
Goodwill (Note 3)	1,095	1,095
Property and equipment, net of accumulated depreciation of $59 and $38	0	0
Deferred income taxes (Note 14)	28	1
Related party receivables	0	29
Other assets	94	74
Due from Affiliates	6,787	3,754
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	7,685	6,994
Total assets	15,689	11,947
Secured debt	0	0
Unsecured debt	7,500	4,000
Accounts payable and accrued expenses	78	101
Deferred income	0	0
Deferred income taxes (Note 14)	0	(28)
Taxes payable	79	83
Related party taxes payable	636	643
Related party payables	0	0
Derivative Liability	3	0
Due to Affiliate	0	863
Total liabilities	8,296	5,662
Common stock, $1.00 par value per share, 1,000 shares authorized and 505 and 502 shares issued	0	0
Additional Paid in Capital, Common Stock	5,799	4,785
Accumulated other comprehensive (loss) income (Note 18)	(432)	11
Retained Earnings (Accumulated Deficit)	2,026	1,489
Total stockholders' equity	7,393	6,285
Total liabilities and shareholder's equity	15,689	11,947
Guarantor Subsidiaries [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	2,266	395	1,252	501
Finance receivables, net (Note 4) ($23,109 and $21,781 in VIEs; Note 8)	2,401	612
Leased vehicles, net (Note 6) ($4,595 and $1,803 in VIEs; Note 8)	0	0
Restricted cash (Note 5)	17	20
Goodwill (Note 3)	0	0
Property and equipment, net of accumulated depreciation of $59 and $38	23	5
Deferred income taxes (Note 14)	0	0
Related party receivables	11	0
Other assets	18	5
Due from Affiliates	0	863
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	4,059	3,565
Total assets	8,795	5,465
Secured debt	0	0
Unsecured debt	0	0
Accounts payable and accrued expenses	156	133
Deferred income	0	0
Deferred income taxes (Note 14)	288	161
Taxes payable	0	0
Related party taxes payable	0	0
Related party payables	0	0
Derivative Liability	12	14
Due to Affiliate	4,164	1,474
Total liabilities	4,620	1,782
Common stock, $1.00 par value per share, 1,000 shares authorized and 505 and 502 shares issued	0	0
Additional Paid in Capital, Common Stock	79	79
Accumulated other comprehensive (loss) income (Note 18)	(64)	(8)
Retained Earnings (Accumulated Deficit)	4,160	3,612
Total stockholders' equity	4,175	3,683
Total liabilities and shareholder's equity	8,795	5,465
Non-Guarantor Subsidiaries [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	708	679	37	71
Finance receivables, net (Note 4) ($23,109 and $21,781 in VIEs; Note 8)	30,599	28,670
Leased vehicles, net (Note 6) ($4,595 and $1,803 in VIEs; Note 8)	7,060	3,383
Restricted cash (Note 5)	2,054	1,938
Goodwill (Note 3)	149	145
Property and equipment, net of accumulated depreciation of $59 and $38	149	127
Deferred income taxes (Note 14)	601	358
Related party receivables	373	100
Other assets	366	358
Due from Affiliates	400	0
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	0	0
Total assets	42,459	35,758
Secured debt	25,214	22,073
Unsecured debt	4,717	2,973
Accounts payable and accrued expenses	768	716
Deferred income	392	168
Deferred income taxes (Note 14)	20	(46)
Taxes payable	155	204
Related party taxes payable	0	1
Related party payables	433	368
Derivative Liability	169	146
Due to Affiliate	3,023	2,280
Total liabilities	34,891	28,883
Common stock, $1.00 par value per share, 1,000 shares authorized and 505 and 502 shares issued	690	532
Additional Paid in Capital, Common Stock	4,064	3,833
Accumulated other comprehensive (loss) income (Note 18)	(410)	24
Retained Earnings (Accumulated Deficit)	3,224	2,486
Total stockholders' equity	7,568	6,875
Total liabilities and shareholder's equity	42,459	35,758
Consolidation, Eliminations [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	0	0	0	0
Finance receivables, net (Note 4) ($23,109 and $21,781 in VIEs; Note 8)	0	0
Leased vehicles, net (Note 6) ($4,595 and $1,803 in VIEs; Note 8)	0	0
Restricted cash (Note 5)	0	0
Goodwill (Note 3)	0	0
Property and equipment, net of accumulated depreciation of $59 and $38	0	0
Deferred income taxes (Note 14)	(288)	0
Related party receivables	0	0
Other assets	0	(4)
Due from Affiliates	(7,187)	(4,617)
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	(11,744)	(10,559)
Total assets	(19,219)	(15,180)
Secured debt	0	0
Unsecured debt	0	0
Accounts payable and accrued expenses	0	(4)
Deferred income	0	0
Deferred income taxes (Note 14)	(288)	0
Taxes payable	0	0
Related party taxes payable		(1)
Related party payables	0	0
Derivative Liability	0	0
Due to Affiliate	(7,187)	(4,617)
Total liabilities	(7,475)	(4,622)
Common stock, $1.00 par value per share, 1,000 shares authorized and 505 and 502 shares issued	(690)	(532)
Additional Paid in Capital, Common Stock	(4,143)	(3,912)
Accumulated other comprehensive (loss) income (Note 18)	473	(16)
Retained Earnings (Accumulated Deficit)	(7,384)	(6,098)
Total stockholders' equity	(11,744)	(10,558)
Total liabilities and shareholder's equity	$ (19,219)	$ (15,180)