EXIT COSTS AND RESTRUCTURING RESERVES - Narrative (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 27	$ 101
Restructuring charges incurred	29	124
Outside Services
Restructuring Cost and Reserve [Line Items]
Restructuring costs	6	24
Salaries & Employee Benefits
Restructuring Cost and Reserve [Line Items]
Restructuring costs	3
Other Restructuring
Restructuring Cost and Reserve [Line Items]
Restructuring costs		12
Restructuring charges incurred		7
Employee Severance | Salaries & Employee Benefits
Restructuring Cost and Reserve [Line Items]
Restructuring costs		41
Restructuring charges incurred	5	43
Facility Closing | Occupancy & Equipment
Restructuring Cost and Reserve [Line Items]
Restructuring costs	18	18
Restructuring charges incurred	$ 18	24
Building Impairment | Occupancy & Equipment
Restructuring Cost and Reserve [Line Items]
Impairment charges		6
Software expense | Amortization of software
Restructuring Cost and Reserve [Line Items]
Restructuring costs		6
Spinoff
Restructuring Cost and Reserve [Line Items]
Restructuring charges incurred		17
Employee Severance | Salaries & Employee Benefits
Restructuring Cost and Reserve [Line Items]
Restructuring charges incurred		3
Facility Closing | Occupancy & Equipment
Restructuring Cost and Reserve [Line Items]
Restructuring charges incurred		3
Facility Closing | Outside Services
Restructuring Cost and Reserve [Line Items]
Restructuring charges incurred		$ 4