Employee Benefit Plans Plan Asset Allocation, Mix of Investments (Details)	12 Months Ended
	Dec. 31, 2016 Rate
Equity Securities, Investment in Single Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit pension plan asset allocation objective, high target percent	5.00%
Equity securities and international mutual funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit pension plan asset allocation objective, low target percent	38.00%
Defined benefit pension plan asset allocation objective, high target percent	58.00%
Debt securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit pension plan asset allocation objective, low target percent	40.00%
Defined benefit pension plan asset allocation objective, high target percent	60.00%
Cash and cash equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit pension plan asset allocation objective, low target percent	0.00%
Defined benefit pension plan asset allocation objective, high target percent	5.00%