Employee Benefits (Weighted-Average Actuarial Assumptions for Benefit Obligations - Retirement Plans) (Details)		12 Months Ended
	Feb. 28, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Remeasurement Date	Feb. 28, 2014
Retirement Income Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate	4.60%	4.57%	4.00%	4.90%
Rate of compensation increase		4.50%	4.50%
Defined Benefit Plan, Effect of One Percentage Point Increase on Discount Rate		1.00%
Defined Benefit Plan, Decrease in Projected Benefit Obiligation, Percentage		11.40%
Defined Benefit Plan, Effect of One Percentage Point Decrease on Discount Rate		1.00%
Defined Benefit Plan, Increase in Projected Benefit Obiligation, Percentage		14.00%
Supplemental Employee Retirement Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate		3.99%	3.40%
Excess Benefit Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate	4.50%	4.59%	4.10%	4.90%
Rate of compensation increase		4.50%	4.50%