Derivative Instruments (Details Textual) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Derivative Instruments (Textual) [Abstract]
Junior subordinated debentures	$ 75,000		$ 75,000
Variable interest rate of derivatives, description			the three-month LIBOR plus a pre-determined spread
August 2012 [Member]
Derivative Instruments (Textual) [Abstract]
Number of derivative instruments terminated (derivative instruments)			2
Derivative instruments deferred gain			1,679
Designated as hedging instruments [Member]
Derivative Instruments (Textual) [Abstract]
Derivative Liabilities	1,904		1,904		2,164
Deferred gains amortized into net interest income	37	115	203	419
August Two Thousand and Twelve [Member]
Derivative Instruments (Textual) [Abstract]
Number of derivative instruments terminated (derivative instruments)			2
Derivative instruments deferred gain			1,679
Interest rate contracts with corporate customers [Member]
Derivative Instruments (Textual) [Abstract]
Junior subordinated debentures	76,484		76,484
Offsetting interest rate contracts with other financial institutions [Member]
Derivative Instruments (Textual) [Abstract]
Junior subordinated debentures	76,484		76,484
Interest rate swaps [Member]
Derivative Instruments (Textual) [Abstract]
Junior subordinated debentures	32,000		32,000
Commitments to fund fixed-rate residential mortgage loans [Member]
Derivative Instruments (Textual) [Abstract]
Junior subordinated debentures	80,076		80,076		72,757
Commitments to sell residential mortgage loans [Member]
Derivative Instruments (Textual) [Abstract]
Junior subordinated debentures	$ 74,542		$ 74,542		$ 100,000