Employee Benefit Plans (Pre-tax Amounts Recognized in Accumulated Other Comprehensive Loss) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)
Pension Benefits
Details of the pre-tax amounts recognized in accumulated other comprehensive loss
Balance at beginning of year, Unamortized Actuarial Net Losses	$ 3,747
Balance at beginning of year, Unamortized Prior Service Costs	0
Amounts arising during the period, Unamortized Actuarial Net Losses	(282)
Amounts arising during the period, Unamortized Prior Service Costs	0
Amounts recognized as a component of net periodic benefit cost, Unamortized Actuarial Net Losses	(243)
Amounts recognized as a component of net periodic benefit cost, Unamortized Prior Service Costs	0
Balance at end of year, Unamortized Actuarial Net Losses	3,222
Balance at end of year, Unamortized Prior Service Costs	0
Postretirement Benefits
Details of the pre-tax amounts recognized in accumulated other comprehensive loss
Balance at beginning of year, Unamortized Actuarial Net Losses	(7,506)
Balance at beginning of year, Unamortized Prior Service Costs
Amounts arising during the period, Unamortized Actuarial Net Losses	(1,623)
Amounts arising during the period, Unamortized Prior Service Costs	0
Amounts recognized as a component of net periodic benefit cost, Unamortized Actuarial Net Losses	0
Amounts recognized as a component of net periodic benefit cost, Unamortized Prior Service Costs	910
Balance at end of year, Unamortized Actuarial Net Losses	(9,129)
Balance at end of year, Unamortized Prior Service Costs	$ 910