Accumulated Other Comprehensive Loss (Details 1) - USD ($) $ in Thousands		3 Months Ended				9 Months Ended
		Sep. 30, 2018		Sep. 30, 2017		Sep. 30, 2018	[2]	Sep. 30, 2017	[2]
Realized (gains) losses on sale of securities
Net realized (gains) losses on investment securities		$ 0	[1]	$ (56)	[1]	$ 148		$ (115)
Provision for income tax expense		0	[1]	19	[1]	(31)		39
Net of tax		0	[1]	(37)	[1]	117		(76)
Amortization of estimated defined benefit pension plan loss
Other expense		490	[1]	0	[1]	1,470		(318)
Provision for income taxes		(103)	[3]	0	[3]	(309)		108
Net of tax		387	[3]	0	[3]	1,161		(210)
Total reclassifications for the period	[4]	$ 387	[1]	$ (37)	[1]	$ 1,278		$ (286)

[1] Amounts in parentheses indicate credits.

[2] Amounts in parentheses indicate income and other amounts indicate expenses.

[3] Amounts in parentheses indicate credits.

[4] Amounts in parentheses indicate debits on the Consolidated Balance Sheets.