Investment Securities (Pooled Trust Preferred Collateralized Debt Obligations) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($) entity	Mar. 31, 2018 USD ($)	Dec. 31, 2018 USD ($)
Fair Value, available for sale	$ 373,937		$ 370,875
Unrealized loss	(2,856)		$ (5,648)
Realized losses YTD	$ 444	$ 154
Percentage of recovery estimate depository institutions	10.00%
Percentage of recovery estimate insurance companies	15.00%
Pooled Trust Preferred Security [Member]
Original Par	$ 3,000
Pooled Trust Preferred Security [Member] | U S Capital Funding I [Member]
Class	B1
Original Par	$ 3,000
Book Value	2,996
Fair Value, available for sale	2,353
Unrealized loss	(643)
Realized losses YTD
Number of Banks / Insurance Cos. Currently Performing | entity	24
Total Number of Banks and Insurance Cos. In Issuance (Unique) | entity	26
Actual Deferrals/Defaults (as a % of original collateral)	7.95%
Total Projected Defaults (as a % of performing collateral)	5.78%
Excess subordination (after taking into account best estimate of future deferrals/defaults)	6.69%
Minimum | Pooled Trust Preferred Security [Member] | U S Capital Funding I [Member]
Class	Caa1