Consolidated Statements of Comprehensive Income (Unaudited) (Parenthetical) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Other comprehensive (loss) income, before tax
Unrealized net holding (losses) gains arising during the period, pre-tax amounts	$ (24,712)	$ (309)	$ (26,464)	$ (335)
Reclassification adjustment for net gains related to securities available for sale included in net income, pre-tax amounts	(61)	97	1,084	552
Amortization of prior service cost and actuarial gains, pre-tax amounts	$ 710	$ 856	$ 1,536	$ 1,713