Investment Securities (Available For Sale Securities Continuous Unrealized Loss Position Fair Value) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Net Investment Income [Line Items]
Investment securities estimated fair value, less than 12 months	$ 210,920	$ 270,224
Investment securities estimated fair value, 12 months or more	19,566	5,584
Investment securities estimated fair value, total	230,486	275,808
Investment securities unrealized losses, less than 12 months	(2,577)	(4,354)
Investment securities unrealized losses,12 months or more	(219)	(210)
Investment securities unrealized losses, total	(2,796)	(4,564)
Held-to-maturity securities, continuous unrealized loss position, less than twelve months, fair value	6,803	9,583
Held-to-maturity securities, continuous unrealized loss position, twelve months or longer, fair value	0	0
Held-to-maturity securities, continuous unrealized loss position, fair value	6,803	9,583
Held-to-maturity securities, continuous unrealized loss position, less than 12 months, accumulated loss	(209)	(250)
Held-to-maturity securities, continuous unrealized loss position, 12 months or longer, accumulated loss	0	0
Held-to-maturity securities, continuous unrealized loss position, accumulated loss	(209)	(250)
U.S. Agency MBS
Net Investment Income [Line Items]
Investment securities estimated fair value, less than 12 months	43,949	51,082
Investment securities estimated fair value, 12 months or more	3,945	1,733
Investment securities estimated fair value, total	47,894	52,815
Investment securities unrealized losses, less than 12 months	(300)	(786)
Investment securities unrealized losses,12 months or more	(17)	(13)
Investment securities unrealized losses, total	(317)	(799)
Held-to-maturity securities, continuous unrealized loss position, less than twelve months, fair value	4,868	7,641
Held-to-maturity securities, continuous unrealized loss position, twelve months or longer, fair value	0	0
Held-to-maturity securities, continuous unrealized loss position, fair value	4,868	7,641
Held-to-maturity securities, continuous unrealized loss position, less than 12 months, accumulated loss	(110)	(148)
Held-to-maturity securities, continuous unrealized loss position, 12 months or longer, accumulated loss	0	0
Held-to-maturity securities, continuous unrealized loss position, accumulated loss	(110)	(148)
Non-Agency MBS
Net Investment Income [Line Items]
Investment securities estimated fair value, less than 12 months	160,190	211,909
Investment securities estimated fair value, 12 months or more	13,734	1,933
Investment securities estimated fair value, total	173,924	213,842
Investment securities unrealized losses, less than 12 months	(2,062)	(3,268)
Investment securities unrealized losses,12 months or more	(140)	(140)
Investment securities unrealized losses, total	(2,202)	(3,408)
U.S. Agency asset-backed securities
Net Investment Income [Line Items]
Investment securities estimated fair value, less than 12 months	0	0
Investment securities estimated fair value, 12 months or more	1,887	1,918
Investment securities estimated fair value, total	1,887	1,918
Investment securities unrealized losses, less than 12 months	0	0
Investment securities unrealized losses,12 months or more	(62)	(57)
Investment securities unrealized losses, total	(62)	(57)
Corporate Securities
Net Investment Income [Line Items]
Investment securities estimated fair value, less than 12 months	6,781	6,709
Investment securities estimated fair value, 12 months or more	0	0
Investment securities estimated fair value, total	6,781	6,709
Investment securities unrealized losses, less than 12 months	(215)	(287)
Investment securities unrealized losses,12 months or more	0	0
Investment securities unrealized losses, total	(215)	(287)
Mutual fund
Net Investment Income [Line Items]
Investment securities estimated fair value, less than 12 months		524
Investment securities estimated fair value, total		524
Investment securities unrealized losses, less than 12 months		(13)
Investment securities unrealized losses, total		(13)
Obligations of state and political subdivisions
Net Investment Income [Line Items]
Held-to-maturity securities, continuous unrealized loss position, less than twelve months, fair value	1,935	1,942
Held-to-maturity securities, continuous unrealized loss position, twelve months or longer, fair value	0	0
Held-to-maturity securities, continuous unrealized loss position, fair value	1,935	1,942
Held-to-maturity securities, continuous unrealized loss position, less than 12 months, accumulated loss	(99)	(102)
Held-to-maturity securities, continuous unrealized loss position, 12 months or longer, accumulated loss	0	0
Held-to-maturity securities, continuous unrealized loss position, accumulated loss	$ (99)	$ (102)