Accumulated Other Comprehensive Income (Loss) Accumulated Other Comprehensive Income (Loss) (Details Textual) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Equity [Abstract]
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, Tax	$ 100,000	$ 100,000	$ 100,000	$ 200,000
Other Comprehensive Income (Loss), Available-for-sale Securities, Tax	$ 0	$ (100,000)	$ 0	$ 400,000