Employee Benefits Allocation of Plan Assets (Details)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Allocation of Plan Assets
Defined Benefit Plan, Target Plan Asset Allocations	100.00%
Defined Benefit Plan, Actual Plan Asset Allocations	100.00%	100.00%
Equity securities
Allocation of Plan Assets
Defined Benefit Plan, Target Plan Asset Allocations	23.00%
Defined Benefit Plan, Actual Plan Asset Allocations	22.00%	22.00%
Fixed income securities
Allocation of Plan Assets
Defined Benefit Plan, Target Plan Asset Allocations	41.00%
Defined Benefit Plan, Actual Plan Asset Allocations	38.00%	46.00%
Real estate
Allocation of Plan Assets
Defined Benefit Plan, Target Plan Asset Allocations	8.00%
Defined Benefit Plan, Actual Plan Asset Allocations	7.00%	5.00%
Other plan assets
Allocation of Plan Assets
Defined Benefit Plan, Target Plan Asset Allocations	28.00%
Defined Benefit Plan, Actual Plan Asset Allocations	33.00%	27.00%