Retirement Plans and Profit Sharing Arrangements (Threadneedle Profit Sharing Plan) (Details 10) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Profit sharing plan [Member]
Defined Benefit, Threadneedle Profit Sharing Plan [Abstract]
Compensation expense (benefit) related to the employee profit sharing plan	$ 60	$ 66	$ 69