EXIT COSTS AND RESTRUCTURING RESERVES - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 0	$ 26,000,000	$ 101,000,000
Restructuring charges incurred	2,000,000	31,000,000	124,000,000
Outside Services
Restructuring Cost and Reserve [Line Items]
Restructuring costs		8,000,000
Salaries & Employee Benefits | Salaries & Employee Benefits
Restructuring Cost and Reserve [Line Items]
Restructuring costs		1,000,000	41,000,000
Restructuring charges incurred	2,000,000	5,000,000	43,000,000
Occupancy & Equipment | Occupancy & Equipment
Restructuring Cost and Reserve [Line Items]
Restructuring costs		17,000,000	18,000,000
Restructuring charges incurred	$ 0	$ 18,000,000	24,000,000
Occupancy & Equipment | Outside Services
Restructuring Cost and Reserve [Line Items]
Restructuring costs			24,000,000
Building Impairment | Occupancy & Equipment
Restructuring Cost and Reserve [Line Items]
Impairment charges			6,000,000
Software expense | Amortization of software
Restructuring Cost and Reserve [Line Items]
Restructuring costs			6,000,000
Other
Restructuring Cost and Reserve [Line Items]
Restructuring costs			12,000,000
Spinoff
Restructuring Cost and Reserve [Line Items]
Restructuring charges incurred			17,000,000
Employee Severance | Salaries & Employee Benefits
Restructuring Cost and Reserve [Line Items]
Restructuring charges incurred			3,000,000
Facility Closing | Occupancy & Equipment
Restructuring Cost and Reserve [Line Items]
Restructuring charges incurred			3,000,000
Facility Closing | Outside Services
Restructuring Cost and Reserve [Line Items]
Restructuring charges incurred			4,000,000
Facility Closing | Other
Restructuring Cost and Reserve [Line Items]
Restructuring charges incurred			$ 7,000,000