Derivative Financial Instruments (Details 2) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Asset derivatives
Gross amount	$ 105	$ 103
Counter- party netting	(3)	(2)
Total asset derivatives	102	101
Liability derivatives
Gross amount	(330)	(329)
Counter- party netting	4	0
Total liability derivatives	(326)	(329)
OTC derivatives
Asset derivatives
Gross amount	8	14
Counter- party netting	(7)	(2)
Cash collateral (received) pledged	0	(4)
Total asset derivatives	1	8
Securities collateral (received) pledged	2	(1)
Net amount	3	7
Liability derivatives
Gross amount	(5)	(5)
Counter- party netting	7	2
Cash collateral (received) pledged	(4)	0
Total liability derivatives	(2)	(3)
Securities collateral (received) pledged	2	4
Net amount	$ 0	$ 1