Investment Securities (Credit Ratings of Non-Agency CMO's, Non-Agency MBS and Asset Backed Securities) (Details)	Jun. 30, 2011		Dec. 31, 2010
Non-agency CMOs [Member]
% of Investment Securities Portfolio	2.00%	[1]	3.00%	[1]
AAA	0.00%		1.00%
Other Investment Grade	12.00%		11.00%
Below Investment Grade or Not Rated	88.00%		88.00%
Non-agency MBS [Member]
% of Investment Securities Portfolio	2.00%	[1]	2.00%	[1]
AAA	0.00%		0.00%
Other Investment Grade	5.00%		6.00%
Below Investment Grade or Not Rated	95.00%		94.00%

[1] Calculated based on the amortized cost of the major security type presented divided by the amortized cost of our total investment securities portfolio as of the end of each period.