Supplemental Comprehensive Income Disclosures (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Supplemental Comprehensive Income Disclosures [Abstract]
Unrealized holding gains on securities arising during the period	$ (4,275)	$ 99
Non-credit related gains (losses) on securities not expected to be sold	1,864	1,498
Reclassification adjustment for gains on securities included in net income	(4)	0
Total available for sale securities	(2,415)	1,597
Total other comprehensive income	(2,415)	1,597
Unrealized holding gains on securities arising during the period	1,495	(34)
Non-credit related gains (losses) on securities not expected to be sold	(652)	(524)
Reclassification adjustment for gains on securities included in net income	1	0
Total available for sale securities	844	(558)
Total other comprehensive income	844	(558)
Unrealized holding gains on securities arising during the period	(2,780)	65
Non-credit related gains (losses) on securities not expected to be sold	1,212	974
Reclassification adjustment for gains on securities included in net income	(3)	0
Total available for sale securities	(1,571)	1,039
Other comprehensive income (loss)	$ (1,571)	$ 1,039