Pension Plans (Details 2) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2015
Components of net periodic pension cost
Interest cost	$ 239,000,000	$ 217,000,000	$ 479,000,000	$ 434,000,000
Expected return on plan assets	(291,000,000)	(275,000,000)	(581,000,000)	(551,000,000)
Recognized net actuarial loss	38,000,000	1,000,000	75,000,000	3,000,000
Total net periodic pension cost	(14,000,000)	(57,000,000)	(27,000,000)	(114,000,000)
Employer contribution	$ 70,000	$ 45,000	$ 70,000	$ 45,000
Scenario, Forecast
Change in plan assets:
Expected contributions in current fiscal year					$ 425,000