CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
CONSOLIDATED BALANCE SHEETS
Securities held-to-maturity, fair value (in dollars)	$ 80,505	$ 50,964
Preferred stock, par value (in dollars per share)
Preferred stock, shares authorized	10,000,000	10,000,000
Series C convertible perpetual preferred stock, shares issued	21,004	21,004
Series C convertible perpetual preferred stock, shares outstanding	21,004	21,004
Series C convertible perpetual preferred stock, liquidation preference (in dollars)	$ 21,004	$ 21,004
Common stock, par value per share
Common stock, shares authorized	60,000,000	60,000,000
Common stock, shares issued	26,341,021	26,322,147
Common stock, shares outstanding	26,341,021	26,322,147