Consolidated Statements Of Comprehensive Income (USD $) In Thousands, unless otherwise specified	9 Months Ended						9 Months Ended
	Sep. 30, 2012 Accumulated Net Unrealized Investment Gain (Loss) [Member]	Sep. 30, 2011 Accumulated Net Unrealized Investment Gain (Loss) [Member]	Sep. 30, 2012 Unrecognized Net Pension Costs [Member]	Dec. 31, 2011 Unrecognized Net Pension Costs [Member]	Sep. 30, 2011 Unrecognized Net Pension Costs [Member]	Dec. 31, 2010 Unrecognized Net Pension Costs [Member]	Sep. 30, 2012 Accumulated Other Comprehensive Income (Loss) [Member]	Sep. 30, 2011 Accumulated Other Comprehensive Income (Loss) [Member]
Beginning Balance	$ (354)	$ (19,806)	$ (12,922)	$ (12,922)	$ (7,933)	$ (7,933)	$ (13,276)	$ (27,739)
Other comprehensive income	4,028	16,326					4,028	16,326
Ending Balance	$ 3,674	$ (3,480)	$ (12,922)	$ (12,922)	$ (7,933)	$ (7,933)	$ (9,248)	$ (11,413)