Retirement Plans (Tables)

9 Months Ended

Sep. 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						Nine Months Ended
	September 30,						September 30,
	2017			2016			2017			2016
	(In millions)
Service cost	$	13		$	15		$	41		$	47
Interest cost		26			27			78			83
Expected return on plan assets		(42	)		(41	)		(125	)		(125	)
Amortization of unrecognized net actuarial losses		13			15			46			47
Settlement loss		4			—			11			—
Pension expense	$	14		$	16		$	51		$	52