Employee Benefits Plans (Details) - The assumptions used to determine the plan’s financial status and postretirement benefit cost:	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Deferred Compensation Plan [Member]
Employee Benefits Plans (Details) - The assumptions used to determine the plan’s financial status and postretirement benefit cost: [Line Items]
Discount rate for funded status	3.55%	3.50%
Discount rate for benefit cost	3.50%	4.00%
Supplemental Employee Retirement Plan [Member]
Employee Benefits Plans (Details) - The assumptions used to determine the plan’s financial status and postretirement benefit cost: [Line Items]
Discount rate for funded status	3.65%	3.50%
Discount rate for benefit cost	3.50%	4.00%
Other Postretirement Benefit Plan [Member]
Employee Benefits Plans (Details) - The assumptions used to determine the plan’s financial status and postretirement benefit cost: [Line Items]
Discount rate for funded status	3.20%	3.10%
Discount rate for benefit cost	3.10%	3.50%
Health care cost assumed trend rate for next year	6.50%	7.00%
Rate that the cost trend rate gradually declines to	5.50%	5.50%
Year that the rate reaches the rate it is assumed to remain at	2018	2018