Stockholders' Equity (Details Textual) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 29, 2011
Stockholders Equity (Additional Textual) [Abstract]
Maximum limit to include the preferred securities in Tier 1 Capital	$ 5,836,751	$ 5,608,825	$ 5,472,306	$ 10,000,000
Stockholders' equity (Textual) [Abstract]
Minimum Tier 1 Ratio to be well capitalized	6.00%
Minimum combined Tier 1 and Tier 2 Ratio to be well capitalized	10.00%
Minimum Leverage Ratio to be well capitalized	5.00%
Maximum [Member]
Stockholders Equity (Additional Textual) [Abstract]
Maximum limit to include the preferred securities in Tier 1 Capital	$ 10,000,000