Other Assets (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Other Assets [Abstract]
Accounts receivable	$ 388	$ 359
Interest and dividends receivable	241	180
Other investments	180	$ 72
Deferred tax asset – net	145
Other	119	$ 59
Prepaid expenses	101	110
Total other assets	$ 1,174	$ 780