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Investment Securities (Investments Gross Unrealized Losses And Fair Value) (Details) - USD ($) $ in Thousands | Jun. 30, 2019 | Dec. 31, 2018
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Investment [Line Items] |  |
Securities available for sale, Less than 12 months, Fair Value | $ 14,276 | $ 251
Securities available for sale, Less than 12 months, Unrealized Losses | 29 | 1
Securities available for sale, 12 months or longer, Fair Value | 102,611 | 438,290
Securities available for sale, 12 months or longer, Unrealized Losses | 653 | 10,749
Securities available for sale, Fair Value, Total | 116,887 | 438,541
Securities available for sale, Unrealized Losses, Total | 682 | 10,750
Securities held to maturity, Less than 12 months, Fair Value | 9,185 | 50,519
Securities held to maturity, Less than 12 months, Unrealized Losses | 11 | 181
Securities held to maturity, 12 months or longer, Fair Value | 130,963 | 234,507
Securities held to maturity, 12 months or longer, Unrealized Losses | 1,543 | 7,718
Securities held to maturity, Fair Value, Total | 140,148 | 285,026
Securities held to maturity, Unrealized Losses, Total | 1,554 | 7,899
Total Securities, Less than 12 months, Fair Value | 23,461 | 50,770
Total Securities, Less than 12 months, Unrealized Losses | 40 | 182
Total Securities, 12 months or longer, Fair Value | 233,574 | 672,797
Total Securities, 12 months or longer, Unrealized Losses | 2,196 | 18,467
Total Securities, Fair Value | 257,035 | 723,567
Total Securities, Unrealized Losses | 2,236 | 18,649
U.S. Government Agency And Government Sponsored Enterprises [Member] |  |
Investment [Line Items] |  |
Securities available for sale, 12 months or longer, Fair Value | 18,952 | 152,028
Securities available for sale, 12 months or longer, Unrealized Losses | 58 | 3,074
Securities available for sale, Fair Value, Total | 18,952 | 152,028
Securities available for sale, Unrealized Losses, Total | 58 | 3,074
State And Political Subdivisions [Member] |  |
Investment [Line Items] |  |
Securities held to maturity, Less than 12 months, Fair Value |  | 35,751
Securities held to maturity, Less than 12 months, Unrealized Losses |  | 91
Securities held to maturity, 12 months or longer, Fair Value | 4,631 | 49,534
Securities held to maturity, 12 months or longer, Unrealized Losses | 19 | 1,120
Securities held to maturity, Fair Value, Total | 4,631 | 85,285
Securities held to maturity, Unrealized Losses, Total | 19 | 1,211
Collateralized Mortgage Obligations [Member] | Federal National Mortgage Association [Member] |  |
Investment [Line Items] |  |
Securities available for sale, Less than 12 months, Fair Value | 67 |
Securities available for sale, Less than 12 months, Unrealized Losses | 1 |
Securities available for sale, 12 months or longer, Fair Value | 16 | 56
Securities available for sale, Fair Value, Total | 83 | 56
Securities available for sale, Unrealized Losses, Total | 1 |
Securities held to maturity, Less than 12 months, Fair Value | 6,763 |
Securities held to maturity, Less than 12 months, Unrealized Losses | 8 |
Securities held to maturity, 12 months or longer, Fair Value | 37,056 | 57,973
Securities held to maturity, 12 months or longer, Unrealized Losses | 584 | 2,179
Securities held to maturity, Fair Value, Total | 43,819 | 57,973
Securities held to maturity, Unrealized Losses, Total | 592 | 2,179
Collateralized Mortgage Obligations [Member] | Federal Home Loan Mortgage Corporation [Member] |  |
Investment [Line Items] |  |
Securities available for sale, 12 months or longer, Fair Value | 5 | 6
Securities available for sale, Fair Value, Total | 5 | 6
Securities held to maturity, 12 months or longer, Fair Value | 52,528 | 75,603
Securities held to maturity, 12 months or longer, Unrealized Losses | 535 | 2,597
Securities held to maturity, Fair Value, Total | 52,528 | 75,603
Securities held to maturity, Unrealized Losses, Total | 535 | 2,597
Collateralized Mortgage Obligations [Member] | Government National Mortgage Association [Member] |  |
Investment [Line Items] |  |
Securities held to maturity, 12 months or longer, Fair Value | 11,586 | 17,263
Securities held to maturity, 12 months or longer, Unrealized Losses | 93 | 535
Securities held to maturity, Fair Value, Total | 11,586 | 17,263
Securities held to maturity, Unrealized Losses, Total | 93 | 535
Mortgage-Backed Securities [Member] |  |
Investment [Line Items] |  |
Securities available for sale, Less than 12 months, Fair Value | 14,276 | 251
Securities available for sale, Less than 12 months, Unrealized Losses | 29 | 1
Securities available for sale, 12 months or longer, Fair Value | 83,659 | 286,262
Securities available for sale, 12 months or longer, Unrealized Losses | 595 | 7,675
Securities available for sale, Fair Value, Total | 97,935 | 286,513
Securities available for sale, Unrealized Losses, Total | 624 | 7,676
Securities held to maturity, Less than 12 months, Fair Value | 9,185 | 14,768
Securities held to maturity, Less than 12 months, Unrealized Losses | 11 | 90
Securities held to maturity, 12 months or longer, Fair Value | 126,332 | 184,973
Securities held to maturity, 12 months or longer, Unrealized Losses | 1,524 | 6,598
Securities held to maturity, Fair Value, Total | 135,517 | 199,741
Securities held to maturity, Unrealized Losses, Total | 1,535 | 6,688
Mortgage-Backed Securities [Member] | Federal National Mortgage Association [Member] |  |
Investment [Line Items] |  |
Securities available for sale, Less than 12 months, Fair Value | 14,209 | 251
Securities available for sale, Less than 12 months, Unrealized Losses | 28 | 1
Securities available for sale, 12 months or longer, Fair Value | 59,305 | 247,615
Securities available for sale, 12 months or longer, Unrealized Losses | 339 | 6,324
Securities available for sale, Fair Value, Total | 73,514 | 247,866
Securities available for sale, Unrealized Losses, Total | 367 | 6,325
Securities held to maturity, Less than 12 months, Fair Value | 2,422 | 1,518
Securities held to maturity, Less than 12 months, Unrealized Losses | 3 | 3
Securities held to maturity, 12 months or longer, Fair Value | 3,442 | 8,695
Securities held to maturity, 12 months or longer, Unrealized Losses | 30 | 258
Securities held to maturity, Fair Value, Total | 5,864 | 10,213
Securities held to maturity, Unrealized Losses, Total | 33 | 261
Mortgage-Backed Securities [Member] | Federal Home Loan Mortgage Corporation [Member] |  |
Investment [Line Items] |  |
Securities available for sale, 12 months or longer, Fair Value | 24,333 | 33,918
Securities available for sale, 12 months or longer, Unrealized Losses | 256 | 1,275
Securities available for sale, Fair Value, Total | 24,333 | 33,918
Securities available for sale, Unrealized Losses, Total | 256 | 1,275
Securities held to maturity, Less than 12 months, Fair Value |  | 1,467
Securities held to maturity, Less than 12 months, Unrealized Losses |  | 5
Securities held to maturity, 12 months or longer, Fair Value | 2,643 | 2,923
Securities held to maturity, 12 months or longer, Unrealized Losses | 65 | 188
Securities held to maturity, Fair Value, Total | 2,643 | 4,390
Securities held to maturity, Unrealized Losses, Total | 65 | 193
Mortgage-Backed Securities [Member] | Government National Mortgage Association [Member] |  |
Investment [Line Items] |  |
Securities available for sale, 12 months or longer, Fair Value |  | 4,667
Securities available for sale, 12 months or longer, Unrealized Losses |  | 76
Securities available for sale, Fair Value, Total |  | 4,667
Securities available for sale, Unrealized Losses, Total |  | 76
Securities held to maturity, Less than 12 months, Fair Value |  | 11,783
Securities held to maturity, Less than 12 months, Unrealized Losses |  | 82
Securities held to maturity, 12 months or longer, Fair Value | 19,077 | 22,516
Securities held to maturity, 12 months or longer, Unrealized Losses | 217 | 841
Securities held to maturity, Fair Value, Total | 19,077 | 34,299
Securities held to maturity, Unrealized Losses, Total | $ 217 | $ 923

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