Guarantor Consolidating Financial Statements Current Period Guarantor Balance Sheet (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013	Dec. 31, 2012
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	$ 1,517,000,000	$ 1,074,000,000	$ 1,756,000,000	$ 1,289,000,000
Finance receivables, net	31,722,000,000	29,282,000,000
Restricted cash	2,060,000,000	1,958,000,000
Property and equipment, net	165,000,000	132,000,000
Leased vehicles, net	5,796,000,000	3,383,000,000
Deferred Tax Assets, Net	357,000,000	359,000,000
Goodwill	1,245,000,000	1,240,000,000
Due from Related Parties	195,000,000	129,000,000
Other assets	516,000,000	433,000,000
Due from Affiliates	0	0
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	0	0
Assets	43,573,000,000	37,990,000,000
Secured debt	22,932,000,000	22,073,000,000
Unsecured debt	10,842,000,000	6,973,000,000
Accounts payable and accrued expenses	990,000,000	946,000,000
Deferred income	317,000,000	168,000,000
Deferred income taxes	21,000,000	87,000,000
Taxes payable	239,000,000	287,000,000
Related party taxes payable	877,000,000	643,000,000
Related party payable	603,000,000	368,000,000
Other Liabilities	194,000,000	160,000,000
Due to Affiliate	0	0
Liabilities	37,015,000,000	31,705,000,000
Common stock, $1.00 par value per share, 1,000 shares authorized and 502 issued	0	0
Additional Paid in Capital, Common Stock	4,798,000,000	4,785,000,000
Accumulated Other Comprehensive Income (Loss), Net of Tax	(207,000,000)	11,000,000	27,000,000
Retained Earnings (Accumulated Deficit)	1,967,000,000	1,489,000,000
Total stockholders' equity	6,558,000,000	6,285,000,000
Total liabilities and shareholder's equity	43,573,000,000	37,990,000,000
Parent Company [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	0	0	0	0
Finance receivables, net		0
Restricted cash		0
Property and equipment, net		0
Leased vehicles, net		0
Deferred Tax Assets, Net	22,000,000	1,000,000
Goodwill	1,095,000,000	1,095,000,000
Due from Related Parties	0	29,000,000
Other assets	97,000,000	74,000,000
Due from Affiliates	6,510,000,000	3,754,000,000
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	7,373,000,000	6,994,000,000
Assets	15,097,000,000	11,947,000,000
Unsecured debt	7,500,000,000	4,000,000,000
Accounts payable and accrued expenses	86,000,000	101,000,000
Deferred income	0
Deferred income taxes	0	(28,000,000)
Taxes payable	76,000,000	83,000,000
Related party taxes payable	877,000,000	643,000,000
Related party payable	0
Other Liabilities	0
Due to Affiliate	0	863,000,000
Liabilities	8,539,000,000	5,662,000,000
Additional Paid in Capital, Common Stock	4,798,000,000	4,785,000,000
Accumulated Other Comprehensive Income (Loss), Net of Tax	(207,000,000)	11,000,000
Retained Earnings (Accumulated Deficit)	1,967,000,000	1,489,000,000
Total stockholders' equity	6,558,000,000	6,285,000,000
Total liabilities and shareholder's equity	15,097,000,000	11,947,000,000
Guarantor Subsidiaries [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	809,000,000	395,000,000	1,250,000,000	1,252,000,000
Finance receivables, net	1,901,000,000	612,000,000
Restricted cash	19,000,000	20,000,000
Property and equipment, net	8,000,000	5,000,000
Leased vehicles, net	0	0
Deferred Tax Assets, Net	0	0
Goodwill	0	0
Due from Related Parties	18,000,000	0
Other assets	45,000,000	5,000,000
Due from Affiliates	0	863,000,000
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	3,397,000,000	3,565,000,000
Assets	6,197,000,000	5,465,000,000
Unsecured debt	0	0
Accounts payable and accrued expenses	141,000,000	133,000,000
Deferred income taxes	200,000,000	161,000,000
Taxes payable	0	0
Related party taxes payable		0
Other Liabilities	22,000,000	14,000,000
Due to Affiliate	1,760,000,000	1,474,000,000
Liabilities	2,123,000,000	1,782,000,000
Additional Paid in Capital, Common Stock	79,000,000	79,000,000
Accumulated Other Comprehensive Income (Loss), Net of Tax	(38,000,000)	(8,000,000)
Retained Earnings (Accumulated Deficit)	4,033,000,000	3,612,000,000
Total stockholders' equity	4,074,000,000	3,683,000,000
Total liabilities and shareholder's equity	6,197,000,000	5,465,000,000
Non-Guarantor Subsidiaries [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	708,000,000	679,000,000	506,000,000	37,000,000
Finance receivables, net	29,821,000,000	28,670,000,000
Restricted cash	2,041,000,000	1,938,000,000
Property and equipment, net	157,000,000	127,000,000
Leased vehicles, net	5,796,000,000	3,383,000,000
Deferred Tax Assets, Net	518,000,000	358,000,000
Goodwill	150,000,000	145,000,000
Due from Related Parties	177,000,000	100,000,000
Other assets	374,000,000	358,000,000
Due from Affiliates	0	0
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	0	0
Assets	39,742,000,000	35,758,000,000
Secured debt	22,932,000,000	22,073,000,000
Unsecured debt	3,342,000,000	2,973,000,000
Accounts payable and accrued expenses	763,000,000	716,000,000
Deferred income	317,000,000	168,000,000
Deferred income taxes	4,000,000	(46,000,000)
Taxes payable	163,000,000	204,000,000
Related party taxes payable	1,000,000	1,000,000
Related party payable	603,000,000	368,000,000
Other Liabilities	172,000,000	146,000,000
Due to Affiliate	4,749,000,000	2,280,000,000
Liabilities	33,046,000,000	28,883,000,000
Common stock, $1.00 par value per share, 1,000 shares authorized and 502 issued	698,000,000	532,000,000
Additional Paid in Capital, Common Stock	3,111,000,000	3,833,000,000
Accumulated Other Comprehensive Income (Loss), Net of Tax	(192,000,000)	24,000,000
Retained Earnings (Accumulated Deficit)	3,079,000,000	2,486,000,000
Total stockholders' equity	6,696,000,000	6,875,000,000
Total liabilities and shareholder's equity	39,742,000,000	35,758,000,000
Consolidation, Eliminations [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	0	0		0
Finance receivables, net		0
Restricted cash		0
Property and equipment, net		0
Leased vehicles, net		0
Deferred Tax Assets, Net	(183,000,000)
Goodwill		0
Due from Related Parties	0	0
Other assets	0	(4,000,000)
Due from Affiliates	(6,510,000,000)	(4,617,000,000)
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	(10,770,000,000)	(10,559,000,000)
Assets	(17,463,000,000)	(15,180,000,000)
Unsecured debt	0	0
Accounts payable and accrued expenses	0	(4,000,000)
Deferred income taxes	(183,000,000)
Taxes payable	0	0
Related party taxes payable	(1,000,000)	(1,000,000)
Related party payable	0
Other Liabilities	0
Due to Affiliate	(6,509,000,000)	(4,617,000,000)
Liabilities	(6,693,000,000)	(4,622,000,000)
Common stock, $1.00 par value per share, 1,000 shares authorized and 502 issued	(698,000,000)	(532,000,000)
Additional Paid in Capital, Common Stock	(3,190,000,000)	(3,912,000,000)
Accumulated Other Comprehensive Income (Loss), Net of Tax	230,000,000	(16,000,000)
Retained Earnings (Accumulated Deficit)	(7,112,000,000)	(6,098,000,000)
Total stockholders' equity	(10,770,000,000)	(10,558,000,000)
Total liabilities and shareholder's equity	$ (17,463,000,000)	$ (15,180,000,000)