Income Taxes (Details 3) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Tax credit carryforwards
Operating loss carryforwards	$ 293
Tax credit carryforwards	147
Valuation allowances	70	$ 172
Foreign Country
Tax credit carryforwards
Operating loss carryforwards	232
Operating loss carryforwards with expiration between 2018 and 2023	177
State And Local Jurisdiction
Tax credit carryforwards
Operating loss carryforwards	1,300
Tax credit carryforwards	$ 152