Accumulated Other Comprehensive Income (Loss) Accumulated Other Comprehensive Income (Loss) (Details Textual) - USD ($)	3 Months Ended		6 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Jun. 30, 2017	Sep. 30, 2017	Sep. 30, 2016
Equity [Abstract]
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, Tax	$ 100,000	$ 100,000		$ 200,000	$ 200,000
Other Comprehensive Income (Loss), Available-for-sale Securities, Tax	$ (100,000)	$ 0		$ (200,000)	$ 0