Employee Benefit Plans (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, discretionary contribution by employer	$ 0	$ 5,500,000
Minimum required contribution for 2019	0
Contributions to the CERP	24,000	439,000	$ 21,000
Accumulated benefit obligation	112,100,000	120,700,000
Defined Benefit Plan, Expected Amortization, Next Fiscal Year	2,100,000
Interest cost on projected benefit obligation	$ 3,756,000	$ 3,826,000	$ 3,944,000
Expected long-term rate of return on pension plan assets	5.00%	6.00%	6.00%
Annualized 10-year return for pension plan	7.20%
Rate of return	(1.70%)	9.60%
Pension expense	$ 1,100,000
Expected pension expense for the upcoming fiscal year	$ 2,200,000
Equity securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Long-term investment target mix	35.00%
Fixed Income Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Long-term investment target mix	65.00%
Change due to updated mortality projection scale [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Change in pension plan obligations due to change in mortality assumptions	$ (300,000)
Change in Accounting Estimate, Type [Domain]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Interest cost on projected benefit obligation		$ (900,000)