Accumulated Other Comprehensive Income (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Accumulated Other Comprehensive Income [Abstract]
Accumulated other comprehensive income reclassification adjustments on unrealized (losses) gains on securities	$ 15,907	$ 26,544	$ (26,209)
Accumulated other comprehensive income reclassification adjustments on OTTI	(994)	(1,034)	(4,992)
Other Comprehensive Income (Loss), Reclassification, Pension and Other Postretirement Benefit Plans, Net Gain (Loss) Recognized in Net Periodic Benefit Cost, before Tax	$ 10,334	$ 9,820	$ 8,114