Global Health Care Medical Costs Payable (Details) - Accident and health insurance [Member] - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014	Dec. 31, 2013
Liability For Unpaid Claims And Claims Adjustment Expense [Line Items]
Incurred but not yet reported	$ 1,876	$ 1,777
Reported claims in process	474	288
Phyician incentives and other medical expense payable	109	115
Medical costs payable	$ 2,459	$ 2,180	$ 2,050