Employee Benefit Plans Plan Asset Allocation by Asset Category (Details)	Dec. 31, 2016 Rate	Dec. 31, 2015 Rate
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocation by asset category based on fair values	100.00%	100.00%
Cash and cash equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocation by asset category based on fair values	3.40%	3.50%
Interest bearing deposits in banks [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocation by asset category based on fair values	0.00%	0.80%
Debt securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocation by asset category based on fair values	49.70%	31.20%
Equity securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocation by asset category based on fair values	46.90%	64.30%
Mutual and exchange traded funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan asset allocation by asset category based on fair values	0.00%	0.20%