EMPLOYEE BENEFIT PLANS (Tables)

3 Months Ended

Mar. 31, 2018

Compensation and Retirement Disclosure [Abstract]

Schedule of Net Benefit Costs

Net periodic benefit costs for qualified defined-benefit plans include the following (in millions): 

	Three Months Ended March 31,
	2018			2017
Service cost	$	12		$	10
Pension expense included in Wages and benefits	12			10
Interest cost	20			18
Expected return on assets	(27		)	(27		)
Recognized actuarial loss (gain)	8			7
Pension expense (benefit) included in Nonoperating	$	1		$	(2	)