Securities (Details 5) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Investments in pooled trust preferred securities
Amortized Cost	$ 686,405	$ 1,117	$ 724
Fair Value	674,248	646,805
Trust preferred securities
Investments in pooled trust preferred securities
Amortized Cost	23,749	24,770
Fair Value	18,389	$ 19,469
Unrealized Gain (Loss)	(5,360)
XXIII
Investments in pooled trust preferred securities
Amortized Cost	8,293
Fair Value	5,680
Unrealized Gain (Loss)	$ (2,613)
Issuers currently in deferral or default (percent)	17.00%
XXIV
Investments in pooled trust preferred securities
Amortized Cost	$ 11,242
Fair Value	9,646
Unrealized Gain (Loss)	$ (1,596)
Issuers currently in deferral or default (percent)	24.00%
XXVI
Investments in pooled trust preferred securities
Amortized Cost	$ 4,214
Fair Value	3,063
Unrealized Gain (Loss)	$ (1,151)
Issuers currently in deferral or default (percent)	19.00%