Changes in Accumulated Other Comprehensive Income Balances (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Beginning Balance	$ 6,446
Other comprehensive income (loss):
Change in net actuarial loss	37	(1,468)	(309)
Tax effect on change in net actuarial loss	(13)	514	108
Unrealized holding gains arising during the period	4,388	191	10,324
Tax effect on unrealized gains arising during the period	(1,536)	(67)	(3,614)
Reclassification adjustment for gains included in net income (loss)	(2,189)	(3,633)	(8,402)
Tax effect on reclassification adjustment for gains included in net income	766	1,272	2,941
Other comprehensive income (loss), net of tax	1,453	(3,191)	1,048
Ending Balance	7,899	6,446
Pension Liability [Member]
Beginning Balance	(2,978)	(2,024)	(1,823)
Other comprehensive income (loss):
Change in net actuarial loss	37	(1,468)	(309)
Tax effect on change in net actuarial loss	(13)	514	108
Unrealized holding gains arising during the period	0	0	0
Tax effect on unrealized gains arising during the period	0	0	0
Reclassification adjustment for gains included in net income (loss)	0	0	0
Tax effect on reclassification adjustment for gains included in net income	0	0	0
Other comprehensive income (loss), net of tax	24	(954)	(201)
Ending Balance	(2,954)	(2,978)	(2,024)
Unrealized Gains (Loss) [Member]
Beginning Balance	9,424	11,661	10,412
Other comprehensive income (loss):
Change in net actuarial loss	0	0	0
Tax effect on change in net actuarial loss	0	0	0
Unrealized holding gains arising during the period	4,388	191	10,324
Tax effect on unrealized gains arising during the period	(1,536)	(67)	(3,614)
Reclassification adjustment for gains included in net income (loss)	(2,189)	(3,633)	(8,402)
Tax effect on reclassification adjustment for gains included in net income	766	1,272	2,941
Other comprehensive income (loss), net of tax	1,429	(2,237)	1,249
Ending Balance	10,853	9,424	11,661
Accumulated Other Comprehensive Income (Loss) [Member]
Beginning Balance	6,446	9,637	8,589
Other comprehensive income (loss):
Change in net actuarial loss	37	(1,468)	(309)
Tax effect on change in net actuarial loss	(13)	514	108
Unrealized holding gains arising during the period	4,388	191	10,324
Tax effect on unrealized gains arising during the period	(1,536)	(67)	(3,614)
Reclassification adjustment for gains included in net income (loss)	(2,189)	(3,633)	(8,402)
Tax effect on reclassification adjustment for gains included in net income	766	1,272	2,941
Other comprehensive income (loss), net of tax	1,453	(3,191)	1,048
Ending Balance	$ 7,899	$ 6,446	$ 9,637