Employee Benefit Plans (Cash Flows) (Details)	Dec. 31, 2017 USD ($)
Pension benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
2018	$ 1,112,000
2019	1,110,000
2020	1,165,000
2021	1,223,000
2022	738,000
2023-2027	3,353,000
Total	8,701,000
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
2018	12,000
2019	11,000
2020	10,000
2021	10,000
2022	9,000
2023-2027	34,000
Total	86,000
Minimum
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	410,000
Maximum
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	$ 440,000