Other Comprehensive Income (Details 1) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accumulated balances for component of other comprehensive income, net of tax
Unrealized gains on securities	$ 9,490	$ 16,500	$ 17,759
Non-credit related portion of other-than-temporary impairment on securities	(16,719)	(16,735)	(17,474)
Unrealized losses on derivative instruments	(1,355)	(1,882)	(1,633)
Unrecognized losses on defined benefit pension and post-retirement benefit plans obligations	(7,320)	(7,418)	(6,250)
Total accumulated other comprehensive loss	$ (15,904)	$ (9,535)	$ (7,598)

Accumulated appreciation or loss, net of tax, in value of the total of available-for-sale securities at the end of an accounting period.

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Accumulated change, net of tax, in accumulated gains and losses from derivative instruments designated and qualifying as the effective portion of cash flow hedges. Includes an entity's share of an equity investee's Increase or Decrease in deferred hedging gains or losses.

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