Retirement Plans (Tables)

6 Months Ended

Jun. 30, 2017

Compensation And Retirement Disclosure [Abstract]

Components of Net Periodic Pension Cost

Components of net periodic pension cost consisted of the following:

	Three Months Ended						Six Months Ended
	June 30,						June 30,
	2017			2016			2017			2016
	(In millions)
Service cost	$	14		$	16		$	28		$	32
Interest cost		26			28			52			56
Expected return on plan assets		(42	)		(42	)		(83	)		(84	)
Amortization of unrecognized net actuarial losses		16			16			33			32
Settlement loss		7			—			7			—
Pension expense	$	21		$	18		$	37		$	36