Notes Payable, Federal Home Loan Bank Advances, Other Borrowings, Secured Borrowings And Subordinated Notes (Narrative) (Details) (USD $)	3 Months Ended	6 Months Ended		12 Months Ended
	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Notes payable	$ 1,000,000	$ 1,000,000	$ 1,000,000	$ 1,000,000
Interest rate on loan agreement		4.50%
Loan agreement with unaffiliated banks, amount		(51,000,000)
Revolving Note		50,000,000
Revolving note maturity date		Oct. 28, 2011
Notes payable, due date		Jun. 01, 2015
Revolving note outstanding balance		50,000,000
Interest rate points on borrowings		450
Percentage of commitment fees payment		0.50%
Restructured FHLB advances		146,000,000		220,000,000
Prepayment fees	6,800,000			10,100,000
Customer balances in sweep accounts		77,300,000
Short-term borrowings from brokers		318,400,000
Subordinated notes	55,000,000	40,000,000	55,000,000	50,000,000
Subordinated debentures interest rate		6.84%
Quarterly principal and interest payments		4,300,000
Repayment of subordinated note		10,000,000	5,000,000
Qualifying special purpose entity notes issued, amount		600,000,000
Notes bear an annual interest rate		1.45%
Notes average term, years		2.93
Notes unpaid balance due		Feb. 17, 2014
Interest rate base point on notes		130
Subordinated Debt [Member]
Subordinated notes		44,700,000
Subordinated debentures interest rate		9.50%
Repayment of subordinated note		$ 4,600,000