Investment Securities (Available-for-sale And Held-to-maturity Securities, Continuous Unrealized Loss Position) (Details) $ in Thousands	Dec. 31, 2015 USD ($) security	Dec. 31, 2014 USD ($) security
Available-for-sale, continuous unrealized loss position [Abstract]
Number of securities | security	313	303
Available-for-sale, continuous unrealized loss position, Fair Value [Abstract]
Less than 12 months, Fair Value	$ 455,904	$ 223,234
12 months or longer, Fair Value	222,352	247,898
Total, Fair Value	678,256	471,132
Available-for-sale, continuous unrealized loss position, Unrealized losses [Abstract]
Less than 12 months, Unrealized losses	(5,800)	(2,189)
12 months or longer, Unrealized losses	(2,923)	(2,071)
Total, Unrealized losses	$ (8,723)	$ (4,260)
Held-to-maturity, continuous unrealized loss position [Abstract]
Number of securities | security	2	1
Held-to-maturity, continuous unrealized loss position, Fair Value [Abstract]
Less than 12 months, Fair Value	$ 25,563
12 months or longer, Fair Value	5,558	$ 5,144
Total, Fair Value	31,121	5,144
Held-to-maturity, continuous unrealized loss position, Unrealized losses [Abstract]
Less than 12 months, Unrealized losses	(42)
12 months or longer, Unrealized losses	(3,456)	(3,820)
Total, Unrealized losses	$ (3,498)	$ (3,820)
U.S. Government Agency Securities [Member]
Available-for-sale, continuous unrealized loss position [Abstract]
Number of securities | security	3
Available-for-sale, continuous unrealized loss position, Fair Value [Abstract]
Less than 12 months, Fair Value	$ 16,500
Total, Fair Value	16,500
Available-for-sale, continuous unrealized loss position, Unrealized losses [Abstract]
Less than 12 months, Unrealized losses	(95)
Total, Unrealized losses	$ (95)
Federally insured student loan securities [Member]
Available-for-sale, continuous unrealized loss position [Abstract]
Number of securities | security	18	9
Available-for-sale, continuous unrealized loss position, Fair Value [Abstract]
Less than 12 months, Fair Value	$ 39,880	$ 28,435
12 months or longer, Fair Value	64,883	34,274
Total, Fair Value	104,763	62,709
Available-for-sale, continuous unrealized loss position, Unrealized losses [Abstract]
Less than 12 months, Unrealized losses	(1,832)	(169)
12 months or longer, Unrealized losses	(1,698)	(221)
Total, Unrealized losses	$ (3,530)	$ (390)
Tax-exempt Obligations Of States And Political Subdivisions [Member]
Available-for-sale, continuous unrealized loss position [Abstract]
Number of securities | security	31	97
Available-for-sale, continuous unrealized loss position, Fair Value [Abstract]
Less than 12 months, Fair Value	$ 1,510	$ 21,458
12 months or longer, Fair Value	18,976	46,412
Total, Fair Value	20,486	67,870
Available-for-sale, continuous unrealized loss position, Unrealized losses [Abstract]
Less than 12 months, Unrealized losses	(22)	(134)
12 months or longer, Unrealized losses	(52)	(245)
Total, Unrealized losses	$ (74)	$ (379)
Taxable obligations of states and political subdivisions [Member]
Available-for-sale, continuous unrealized loss position [Abstract]
Number of securities | security	30	24
Available-for-sale, continuous unrealized loss position, Fair Value [Abstract]
Less than 12 months, Fair Value	$ 40,310	$ 499
12 months or longer, Fair Value	7,023	21,088
Total, Fair Value	47,333	21,587
Available-for-sale, continuous unrealized loss position, Unrealized losses [Abstract]
Less than 12 months, Unrealized losses	(450)	(1)
12 months or longer, Unrealized losses	(26)	(102)
Total, Unrealized losses	$ (476)	$ (103)
Residential Mortgage-backed Securities [Member]
Available-for-sale, continuous unrealized loss position [Abstract]
Number of securities | security	63	29
Available-for-sale, continuous unrealized loss position, Fair Value [Abstract]
Less than 12 months, Fair Value	$ 200,820	$ 43,946
12 months or longer, Fair Value	71,043	67,023
Total, Fair Value	271,863	110,969
Available-for-sale, continuous unrealized loss position, Unrealized losses [Abstract]
Less than 12 months, Unrealized losses	(2,155)	(231)
12 months or longer, Unrealized losses	(710)	(647)
Total, Unrealized losses	$ (2,865)	$ (878)
Commercial Mortgage-backed Securities [Member]
Available-for-sale, continuous unrealized loss position [Abstract]
Number of securities | security	37	30
Available-for-sale, continuous unrealized loss position, Fair Value [Abstract]
Less than 12 months, Fair Value	$ 25,899	$ 41,231
12 months or longer, Fair Value	17,539	47,549
Total, Fair Value	43,438	88,780
Available-for-sale, continuous unrealized loss position, Unrealized losses [Abstract]
Less than 12 months, Unrealized losses	(233)	(883)
12 months or longer, Unrealized losses	(337)	(617)
Total, Unrealized losses	$ (570)	$ (1,500)
Commercial Loan Obligation Securities [Member]
Available-for-sale, continuous unrealized loss position [Abstract]
Number of securities | security	5
Available-for-sale, continuous unrealized loss position, Fair Value [Abstract]
Less than 12 months, Fair Value	$ 56,638
12 months or longer, Fair Value	13,855
Total, Fair Value	70,493
Available-for-sale, continuous unrealized loss position, Unrealized losses [Abstract]
Less than 12 months, Unrealized losses	(81)
Total, Unrealized losses	$ (81)
Foreign Debt Securities [Member]
Available-for-sale, continuous unrealized loss position [Abstract]
Number of securities | security	51	53
Available-for-sale, continuous unrealized loss position, Fair Value [Abstract]
Less than 12 months, Fair Value	$ 24,274	$ 24,681
12 months or longer, Fair Value	18,272	14,943
Total, Fair Value	42,546	39,624
Available-for-sale, continuous unrealized loss position, Unrealized losses [Abstract]
Less than 12 months, Unrealized losses	(245)	(203)
12 months or longer, Unrealized losses	(63)	(144)
Total, Unrealized losses	$ (308)	$ (347)
Corporate And Other Debt Securities [Member]
Available-for-sale, continuous unrealized loss position [Abstract]
Number of securities | security	75	61
Available-for-sale, continuous unrealized loss position, Fair Value [Abstract]
Less than 12 months, Fair Value	$ 50,073	$ 62,984
12 months or longer, Fair Value	10,761	16,609
Total, Fair Value	60,834	79,593
Available-for-sale, continuous unrealized loss position, Unrealized losses [Abstract]
Less than 12 months, Unrealized losses	(687)	(568)
12 months or longer, Unrealized losses	(37)	(95)
Total, Unrealized losses	$ (724)	$ (663)
Single Issuers [Member]
Held-to-maturity, continuous unrealized loss position [Abstract]
Number of securities | security	1	1
Held-to-maturity, continuous unrealized loss position, Fair Value [Abstract]
12 months or longer, Fair Value	$ 5,558	$ 5,144
Total, Fair Value	5,558	5,144
Held-to-maturity, continuous unrealized loss position, Unrealized losses [Abstract]
12 months or longer, Unrealized losses	(3,456)	(3,820)
Total, Unrealized losses	$ (3,456)	$ (3,820)
Pooled [Member]
Held-to-maturity, continuous unrealized loss position [Abstract]
Number of securities | security	1
Held-to-maturity, continuous unrealized loss position, Fair Value [Abstract]
Less than 12 months, Fair Value	$ 25,563
Total, Fair Value	25,563
Held-to-maturity, continuous unrealized loss position, Unrealized losses [Abstract]
Less than 12 months, Unrealized losses	(42)
Total, Unrealized losses	$ (42)