Fair Value Measurements (Details 2) - Level 3 - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	$ 1	$ 1
Issuance of guarantees	0	0
Expiration of guarantees	0	0
Balance at end of period	$ 1	$ 1