Fair Value Measurements (Details 1) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Reconciliation of items measured at fair value on a recurring basis that used significant unobservable inputs (Level 3)
Balance at the beginning of the period	$ 15	$ 12	$ 15	$ 11
Total gains or losses included in earnings	0	0	0	0
Total gains or losses included in other comprehensive income	0	0	0	(1)
Purchases and issuances	0	0	0	0
Sales and settlements	0	0	0	0
Transfers in and/or out of Level 3	0	0	0	0
Balance at the end of the period	15	12	15	12
Change in unrealized gains or losses for the period included in earnings for securities held at the end of the reporting period	$ 0	$ 0	$ 0	$ 0