Employee Incentive, Retirement, Deferred Compensation, and Career Achievement Plans (Schedule of Assumptions Used) (Details)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Employee Incentive, Retirement, Deferred Compensation, and Career Achievement Plans [Abstract]
Discount rate	4.62%	4.19%	5.30%
Rate of compensation increase	3.00%	3.00%	3.00%
Investment crediting rate for notional account balances	6.50%	6.50%	6.50%