Derivative Financial Instruments (Details 2) - USD ($) $ in Millions	Jun. 30, 2017	Dec. 31, 2016
Asset derivatives
Gross amount	$ 102	$ 103
Counter- party netting	(1)	(2)
Total asset derivatives	101	101
Liability derivatives
Gross amount	(329)	(329)
Counter- party netting	4	0
Total liability derivatives	(325)	(329)
OTC derivatives
Asset derivatives
Gross amount	7	14
Counter- party netting	(5)	(2)
Cash collateral (received) pledged	(1)	(4)
Total asset derivatives	1	8
Securities collateral (received) pledged	0	(1)
Net amount	1	7
Liability derivatives
Gross amount	(8)	(5)
Counter- party netting	5	2
Cash collateral (received) pledged	(3)	0
Total liability derivatives	(6)	(3)
Securities collateral (received) pledged	3	4
Net amount	$ (3)	$ 1