Investment Securities (Schedule Of Investment Securities Classified As Available-for-sale And Held-to-maturity) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Available-for-sale [Abstract]
Amortized cost	$ 1,251,262,000	$ 701,151,000
Gross unrealized gains	9,164,000	18,135,000
Gross unrealized losses	(7,309,000)	(1,221,000)
Fair value	1,253,117,000	718,065,000
Held-to-maturity [Abstract]
Amortized cost	97,205,000	45,179,000
Gross unrealized gains	2,047,000	254,000
Gross unrealized losses	(4,222,000)	(4,425,000)
Fair value	95,030,000	41,008,000
U.S. Government Agency Securities [Member]
Available-for-sale [Abstract]
Amortized cost	10,680,000	7,255,000
Gross unrealized gains	46,000	245,000
Fair value	10,726,000	7,500,000
Federally Insured Student Loan Securities [Member]
Available-for-sale [Abstract]
Amortized cost	147,717,000	142,851,000
Gross unrealized gains	575,000	1,002,000
Gross unrealized losses	(719,000)	(83,000)
Fair value	147,573,000	143,770,000
Tax-exempt Obligations Of States And Political Subdivisions [Member]
Available-for-sale [Abstract]
Amortized cost	378,180,000	112,393,000
Gross unrealized gains	2,721,000	5,314,000
Gross unrealized losses	(1,951,000)	(2,000)
Fair value	378,950,000	117,705,000
Taxable Obligations Of States And Political Subdivisions [Member]
Available-for-sale [Abstract]
Amortized cost	78,638,000	38,291,000
Gross unrealized gains	1,276,000	3,118,000
Gross unrealized losses	(746,000)	(21,000)
Fair value	79,168,000	41,388,000
Residential Mortgage-backed Securities [Member]
Available-for-sale [Abstract]
Amortized cost	323,199,000	275,197,000
Gross unrealized gains	1,838,000	3,389,000
Gross unrealized losses	(2,263,000)	(779,000)
Fair value	322,774,000	277,807,000
Commercial Mortgage-backed Securities [Member]
Available-for-sale [Abstract]
Amortized cost	118,838,000	92,765,000
Gross unrealized gains	1,919,000	4,298,000
Gross unrealized losses	(410,000)	(32,000)
Fair value	120,347,000	97,031,000
Corporate And Other Debt Securities [Member]
Available-for-sale [Abstract]
Amortized cost	194,010,000	32,399,000
Gross unrealized gains	789,000	769,000
Gross unrealized losses	(1,220,000)	(304,000)
Fair value	193,579,000	32,864,000
Single Issuers [Member]
Held-to-maturity [Abstract]
Amortized cost	21,027,000	18,980,000
Gross unrealized gains	367,000	218,000
Gross unrealized losses	(4,222,000)	(4,241,000)
Fair value	17,172,000	14,957,000
Pooled [Member]
Held-to-maturity [Abstract]
Amortized cost	76,178,000	26,199,000
Gross unrealized gains	1,680,000	36,000
Gross unrealized losses		(184,000)
Fair value	$ 77,858,000	$ 26,051,000