Accumulated Other Comprehensive Income (''AOCI'') (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Changes in AOCI
Balance at the beginning of the period, net of taxes	$ (1,851)	$ (4,029)
Other comprehensive income (loss) before reclassification, net of taxes	493	1,585
Amounts reclassified from other comprehensive income (loss), net of taxes	41	(32)
Net current period other comprehensive income (loss), net	534	1,553
Balance at the end of the period, net of taxes	(1,317)	(2,476)
Unrealized Gains (Losses) on Available-for-Sale Securities and I/O Strips
Changes in AOCI
Balance at the beginning of the period, net of taxes	3,666	(430)
Other comprehensive income (loss) before reclassification, net of taxes	514	1,595
Amounts reclassified from other comprehensive income (loss), net of taxes		(29)
Net current period other comprehensive income (loss), net	514	1,566
Balance at the end of the period, net of taxes	4,180	1,136
Unamortized Unrealized Gain on Available-for-Sale Securities Reclassified to Held-to-Maturity
Changes in AOCI
Balance at the beginning of the period, net of taxes	435	466
Amounts reclassified from other comprehensive income (loss), net of taxes	(8)	(8)
Net current period other comprehensive income (loss), net	(8)	(8)
Balance at the end of the period, net of taxes	427	458
Defined Benefit Pension Plan Items
Changes in AOCI
Balance at the beginning of the period, net of taxes	(5,952)	(4,065)
Other comprehensive income (loss) before reclassification, net of taxes	(21)	(10)
Amounts reclassified from other comprehensive income (loss), net of taxes	49	5
Net current period other comprehensive income (loss), net	28	(5)
Balance at the end of the period, net of taxes	$ (5,924)	$ (4,070)