Securities - (Details 5) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Investments in pooled trust preferred securities
Amortized Cost	$ 704,305	$ 686,405
Securities available for sale	696,885	674,248
Trust preferred securities
Investments in pooled trust preferred securities
Amortized Cost	22,646	23,749
Securities available for sale	17,823	$ 18,389
Unrealized Loss	(4,823)
XXIII
Investments in pooled trust preferred securities
Amortized Cost	8,286
Securities available for sale	5,790
Unrealized Loss	$ (2,496)
Issuers Currently in Deferral or Default (percent)	17.00%
XXIV
Investments in pooled trust preferred securities
Amortized Cost	$ 10,167
Securities available for sale	8,917
Unrealized Loss	$ (1,250)
Issuers Currently in Deferral or Default (percent)	23.00%
XXVI
Investments in pooled trust preferred securities
Amortized Cost	$ 4,193
Securities available for sale	3,116
Unrealized Loss	$ (1,077)
Issuers Currently in Deferral or Default (percent)	19.00%