EXIT COSTS AND RESTRUCTURING RESERVES - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 26	$ 101
Restructuring charges incurred	31	124	$ 31
Outside Services
Restructuring Cost and Reserve [Line Items]
Restructuring costs	8	24
Salaries & Employee Benefits
Restructuring Cost and Reserve [Line Items]
Restructuring costs	1
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	6
Facility Closing | Occupancy & Equipment
Restructuring Cost and Reserve [Line Items]
Restructuring costs	17	18
Restructuring charges incurred	$ 18	24	$ 22
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