Rendering

Component: (Network and Table)
Network
2427402 - Disclosure - Accumulated Other Comprehensive Loss (Rollforward) (Details)
(http://www.ally.com/role/AccumulatedOtherComprehensiveLossRollforwardDetails)
Table(Implied)
Slicers (applies to each fact value in each table cell)
Reporting Entity [Axis]0000040729 (http://www.sec.gov/CIK)
Accumulated Other Comprehensive Income (Loss) [Abstract]Period [Axis]
2016-01-01 - 2016-12-31
2015-01-01 - 2015-12-31
2014-01-01 - 2014-12-31
Accumulated Other Comprehensive Income (Loss) [Abstract]
 
 
 
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax [Abstract]
 
 
 
Beginning Balance Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax
(159,000,000) 
(21,000,000) 
(269,000,000) 
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax, Portion Attributable to Parent
(114,000,000) 
(138,000,000) 
248,000,000  
Ending Balance Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax
(273,000,000) 
 
(159,000,000) 
 
(21,000,000) 
 
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax [Abstract]
 
 
 
Beginning Balance Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax
9,000,000  
36,000,000  
65,000,000  
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax
5,000,000  
(27,000,000) 
(29,000,000) 
Ending Balance Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax
14,000,000  
 
9,000,000  
 
36,000,000  
 
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax [Abstract]
 
 
 
Beginning Balance Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax
8,000,000  
7,000,000  
5,000,000  
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax, Portion Attributable to Parent
0  
1,000,000  
2,000,000  
Ending Balance Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax
8,000,000  
 
8,000,000  
 
7,000,000  
 
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax [Abstract]
 
 
 
Beginning Balance Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax
(89,000,000) 
(88,000,000) 
(77,000,000) 
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax, Portion Attributable to Parent
(1,000,000) 
(1,000,000) 
(11,000,000) 
Ending Balance Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax
(90,000,000) 
 
(89,000,000) 
 
(88,000,000) 
 
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
 
 
 
Accumulated Other Comprehensive Income (Loss), Net of Tax
(231,000,000) 
(66,000,000) 
(276,000,000) 
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent
(110,000,000) 
(165,000,000) 
210,000,000  
Accumulated Other Comprehensive Income (Loss), Net of Tax
(341,000,000) 
 
(231,000,000) 
 
(66,000,000)