Securities (Details Textual) (USD $)	12 Months Ended
	Dec. 31, 2013 Tranche Institutions	Dec. 31, 2012	Dec. 31, 2011
Securities (Additional Textual) [Abstract]
Carrying value of securities held to maturity	$ 4,292,000		$ 13,017,000
Net gain recognized on sale of securities held to maturity	169,000		16,000
Securities classified as held to maturity		0
Securities (Textual) [Abstract]
Investments in pooled trust preferred securities, cost basis	513,594,000
Fair Value	501,254,000	356,311,000
Number of securities representing interests in tranches of trusts (tranches)	4
Number of institutions issuing debt (institutions)	330
Credit related impairment losses	0	0	262,000
Trust preferred securities
Securities (Textual) [Abstract]
Investments in pooled trust preferred securities, cost basis	27,531,000	28,612,000
Fair Value	17,671,000	15,068,000
Credit related impairment losses	0		262,000
Secure government, public and trust deposits
Securities (Textual) [Abstract]
Available for sale securities pledged as collateral	604,571,000	308,362,000
Short-term borrowings
Securities (Textual) [Abstract]
Available for sale securities pledged as collateral	$ 7,626,000	$ 19,006,000