Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2015	Sep. 30, 2014	Dec. 31, 2014	Dec. 31, 2013
Income Tax Contingency [Line Items]
Unrecognized tax benefits			$ 218	$ 199
Foreign Tax Authority [Member]
Income Tax Contingency [Line Items]
Increase in unrecognized tax benefits	$ 15	$ 30
Tax charge resulting from a decision of a foreign tax authority	$ 15	66
Deferred tax asset write off		$ 36