Investment Securities Summary of Gains and Losses from Equity and Debt Securities, and Losses from Other-than-Temporary Impairment (Details) (USD $) In Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Gross Realized Gains	$ 146	$ 5,086	$ 3,799	$ 12,260
Gross Realized Losses	0	(445)	(19)	(463)
Other-than-temporary Impairment Losses	(589)	(2,815)	(2,273)	(11,290)
Net Gains (Losses)	(443)	1,826	1,507	507
Equity Securities [Member]
Gross Realized Gains	146	601	194	1,451
Gross Realized Losses	0	(391)	0	(391)
Other-than-temporary Impairment Losses	(244)	(480)	(575)	(1,813)
Net Gains (Losses)	(98)	(270)	(381)	(753)
Debt Securities [Member]
Gross Realized Gains	0	4,485	3,605	10,809
Gross Realized Losses	0	(54)	(19)	(72)
Other-than-temporary Impairment Losses	(345)	(2,335)	(1,698)	(9,477)
Net Gains (Losses)	$ (345)	$ 2,096	$ 1,888	$ 1,260