Investment Securities (Amortized Cost And Estimated Fair Value Of Investments In Debt Securities By Contractual Maturity) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	$ 973,923	$ 1,028,883
Securities Available-for-Sale, Total Fair value	978,825	1,003,421
Securities Held-to-Maturity, Amortized Cost	350,375	351,808
Securities held-to-maturity, fair value	364,560	351,422
US Treasury and Government [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Amortized Cost	3,445
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Fair Value	$ 3,480
Debt Securities, Available-for-sale, Maturity, after One Through Five Years, Weighted Average Yield	2.50%
Debt Securities, Available-for-sale, Amortized Cost	$ 3,445
Securities Available-for-Sale, Total Fair value	$ 3,480
Available for Sale Securities Weighted Avg Yield	2.50%
US States and Political Subdivisions Debt Securities [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Amortized Cost	$ 3,030
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Fair Value	$ 3,078
Debt Securities, Available-for-sale, Maturity, after One Through Five Years, Weighted Average Yield	2.76%
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Amortized Cost	$ 6,050
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Fair Value	$ 6,129
Debt Securities, Available-for-sale, Maturity, after Five Through Ten Years, Weighted Average Yield	2.69%
Debt Securities, Available-for-sale, Allocated and Single Maturity Date, Maturity, after 10 Years, Amortized Cost	$ 6,960
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after 10 Years, Fair Value	$ 7,043
Debt Securities, Available-for-sale, Maturity, after 10 Years, Weighted Average Yield	3.21%
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Amortized Cost	$ 4,010
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Fair Value	$ 4,141
Held to Maturity Securities weighted avg yield five through ten	3.04%
Held-to-maturity Securities, Debt Maturities, after Five Through Ten Years, Net Carrying Amount	$ 300,101
Held-to-maturity Securities, Debt Maturities, Year Six Through Ten, Fair Value	$ 313,777
Held to Maturity Securities Debt Maturities Years Over Ten weighted avg yield	3.69%
Debt Securities, Available-for-sale, Amortized Cost	$ 16,040
Securities Available-for-Sale, Total Fair value	$ 16,250
Available for Sale Securities Weighted Avg Yield	2.93%
Securities Held-to-Maturity, Amortized Cost	$ 304,111	305,278
Securities held-to-maturity, fair value	$ 317,918	305,808
Held to Maturity Securities weighted avg yield	3.68%
Other Debt Obligations [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Amortized Cost	$ 1,046
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Fair Value	$ 1,069
Debt Securities, Available-for-sale, Maturity, after Five Through Ten Years, Weighted Average Yield	2.77%
Debt Securities, Available-for-sale, Allocated and Single Maturity Date, Maturity, after 10 Years, Amortized Cost	$ 5,105
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after 10 Years, Fair Value	$ 5,242
Debt Securities, Available-for-sale, Maturity, after 10 Years, Weighted Average Yield	2.95%
Debt Securities, Available-for-sale, Amortized Cost	$ 6,151
Securities Available-for-Sale, Total Fair value	$ 6,311
Available for Sale Securities Weighted Avg Yield	2.92%
U.S. Government Sponsored Entities Asset-Backed Securities [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	$ 948,287	1,028,883
Securities Available-for-Sale, Total Fair value	$ 952,784	1,003,421
Available for Sale Securities Weighted Avg Yield	2.36%
Securities Held-to-Maturity, Amortized Cost	$ 46,264	46,530
Securities held-to-maturity, fair value	$ 46,642	$ 45,614
Held to Maturity Securities weighted avg yield	2.82%

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in sixth fiscal year through tenth fiscal year following latest fiscal year. Excludes interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date.

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Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in sixth through tenth fiscal year following latest fiscal year. Excludes interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date.

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in second through fifth fiscal year following latest fiscal year. Excludes interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date.

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Weighted average yield of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), maturing after tenth fiscal year following latest fiscal year. Excludes interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date.

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