Derivative Financial Instruments (Details 2) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Asset derivatives
Gross amount	$ 96	$ 103
Counter- party netting	(1)	(2)
Total asset derivatives	95	101
Liability derivatives
Gross amount	(331)	(329)
Counter- party netting	1	0
Total liability derivatives	(330)	(329)
OTC derivatives
Asset derivatives
Gross amount	5	14
Counter- party netting	(2)	(2)
Cash collateral (received) pledged	(1)	(4)
Total asset derivatives	2	8
Securities collateral (received) pledged	0	(1)
Net amount	2	7
Liability derivatives
Gross amount	(7)	(5)
Counter- party netting	2	2
Cash collateral (received) pledged	0	0
Total liability derivatives	(5)	(3)
Securities collateral (received) pledged	3	4
Net amount	$ (2)	$ 1