Employee Pension and Other Benefit Plans - Employee Pension and Other Benefit Plans (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Pension Plans
Pension and other post-retirement costs, net
Service cost	$ 8	$ 6	$ 23	$ 19
Interest cost	10	10	32	30
Expected return on plan assets	(15)	(12)	(44)	(38)
Amortization, net	6	3	20	10
Settlements	3	3	3	6
Benefit costs, net	12	10	34	27
Other Benefit Plans
Pension and other post-retirement costs, net
Service cost		1	2	2
Interest cost	1	2	4	5
Amortization, net	$ (1)		(1)
Benefit costs, net		$ 3	$ 5	$ 7