v3.3.1.900
EMPLOYEE BENEFIT PLANS - PERIODIC BENEFIT COSTS AND ASSUMPTIONS (DETAILS) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Pension Benefits      
Net Periodic Benefit Costs:      
Service cost $ 35 $ 30 $ 30
Interest cost 33 36 31
Expected return on plan assets (42) (39) (35)
Amortization of prior service cost 1 1 1
Amortization of net loss 12 4 19
Curtailment loss 1   1
Settlement loss recognized 1    
Special termination benefit     3
Net periodic benefit costs $ 41 $ 32 $ 50
Weighted-Average Assumptions to Determine Benefit Obligations      
Discount rate (as a percent) 4.20% 3.80%  
Increase in future compensation levels (as a percent) 3.30% 3.50%  
Weighted-Average Assumptions to Determine the Net Periodic Benefit Cost      
Discount rate (as a percent) 3.80% 4.90% 4.00%
Expected long-term rate of return on assets (as a percent) 6.70% 6.70% 6.60%
Increase in future compensation levels (as a percent) 3.50% 3.50% 3.70%
Postretirement Benefits      
Net Periodic Benefit Costs:      
Interest cost $ 5 $ 6 $ 7
Amortization of net loss   (1)  
Curtailment loss   (2) (2)
Net periodic benefit costs $ 5 $ 3 $ 5
Weighted-Average Assumptions to Determine Benefit Obligations      
Discount rate (as a percent) 11.40% 9.80%  
Weighted-Average Assumptions to Determine the Net Periodic Benefit Cost      
Discount rate (as a percent) 9.80% 10.00% 7.90%