Derivatives and Hedging - Schedule of amounts of derivative gains (losses) recognized in the Consolidated Financial Statements (Details) - Cash Flow Hedging [Member] - Foreign exchange contracts [Member] - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Derivative [Line Items]
Gain (Loss) recognized in accumulated other comprehensive income	$ (10)	$ (1)
Gain (Loss) reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion):	0	(10)
Compensation and Benefits [Member]
Derivative [Line Items]
Gain (Loss) recognized in accumulated other comprehensive income	(2)	5
Gain (Loss) reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion):	1	0
Other General Expenses [Member]
Derivative [Line Items]
Gain (Loss) recognized in accumulated other comprehensive income	(3)	(2)
Gain (Loss) reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion):	0	0
Interest Expense [Member]
Derivative [Line Items]
Gain (Loss) recognized in accumulated other comprehensive income	0	0
Gain (Loss) reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion):	0	(2)
Other Income (Expense) [Member]
Derivative [Line Items]
Gain (Loss) recognized in accumulated other comprehensive income	(5)	(4)
Gain (Loss) reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion):	$ (1)	$ (8)