Stockholders' Equity (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Unrealized Gain (Loss) on Securities
Accumulated Other Comprehensive Income (Loss)
Balance at the beginning	[1]			$ (591)	$ 214
Other comprehensive income (loss), before reclassifications	[1]			3,357	(591)
Amounts reclassified from accumulated other comprehensive income (loss)	[1]			(490)	(8)
Current period other comprehensive income (loss), before tax	[1]			2,867	(599)
Income tax benefit (expense)	[1]			(1,090)	228
Current period other comprehensive income (loss), net of tax	[1]			1,777	(371)
Balance at the end	[1]	$ 1,186	$ (157)	1,186	(157)
Unrecognized Net Pension and Postretirement Costs
Accumulated Other Comprehensive Income (Loss)
Balance at the beginning	[2]			(1,427)	(1,442)
Other comprehensive income (loss), before reclassifications	[2]			39	72
Amounts reclassified from accumulated other comprehensive income (loss)	[2]			0	0
Current period other comprehensive income (loss), before tax	[2]			39	72
Income tax benefit (expense)	[2]			(14)	(27)
Current period other comprehensive income (loss), net of tax	[2]			25	45
Balance at the end	[2]	(1,402)	(1,397)	(1,402)	(1,397)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss)
Balance at the beginning				(2,018)	(1,228)
Other comprehensive income (loss), before reclassifications				3,396	(519)
Amounts reclassified from accumulated other comprehensive income (loss)				(490)	(8)
Current period other comprehensive income (loss), before tax				2,906	(527)
Income tax benefit (expense)				(1,104)	201
Current period other comprehensive income (loss), net of tax				1,802	(326)
Balance at the end		(216)	(1,554)	(216)	(1,554)
Balance at the beginning				(2,018)
Current period other comprehensive income (loss), net of tax		838	$ (833)	1,802	$ (326)
Balance at the end		$ (216)		$ (216)

[1] The pre-tax amounts reclassified from accumulated other comprehensive income (loss) are included in gain on sale of investment securities in the consolidated statements of income.

[2] The pre-tax amounts reclassified from accumulated other comprehensive income (loss) are included in the computation of net periodic pension cost.