Securities - (Details 5) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014
Investments in pooled trust preferred securities
Amortized Cost	$ 659,017		$ 724
Securities available for sale	662,801	$ 553,584
Trust preferred securities
Investments in pooled trust preferred securities
Amortized Cost	24,807	26,400
Securities available for sale	18,890	$ 19,756
Unrealized Loss	(5,917)
XXIII
Investments in pooled trust preferred securities
Amortized Cost	8,510
Securities available for sale	5,882
Unrealized Loss	$ (2,628)
Issuers Currently in Deferral or Default (percent)	18.00%
XXIV
Investments in pooled trust preferred securities
Amortized Cost	$ 12,076
Securities available for sale	9,963
Unrealized Loss	$ (2,113)
Issuers Currently in Deferral or Default (percent)	31.00%
XXVI
Investments in pooled trust preferred securities
Amortized Cost	$ 4,221
Securities available for sale	3,045
Unrealized Loss	$ (1,176)
Issuers Currently in Deferral or Default (percent)	26.00%