Consolidated Statements of Comprehensive Income (unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Other comprehensive income (loss), net of tax:
Unrealized net holding gains (losses) arising during the period, pre-tax amounts	$ 3,730	$ (5,277)	$ 16,941	$ (434)
Reclassification adjustment for net gains related to securities available for sale included in net income, pre-tax amounts	1	26	30	40
Unrealized losses on derivatives (cash flow hedges), pre-tax amounts	(62)	0	(62)	0
Amortization of unrealized net gains and losses related to the reclassification of available for sale investment securities to held to maturity, pre-tax amounts	280	336	576	671
Amortization of prior service cost and actuarial gains, pre-tax amounts	$ 513	$ 561	$ 1,024	$ 1,122