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Securities, Available for Sale (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Sep. 30, 2019 | Sep. 30, 2018 | Sep. 30, 2019 | Sep. 30, 2018 | Dec. 31, 2018
Debt securities, available-for-sale [Abstract] |  |  |  |  |
Amortized cost | $ 924,437 |  | $ 924,437 |  | $ 1,017,626
Unrealized gains | 8,886 |  | 8,886 |  | 1,216
Unrealized losses | 1,150 |  | 1,150 |  | 20,346
Estimated fair value | 932,173 |  | 932,173 |  | 998,496
Sales transactions of securities available for sale [Abstract] |  |  |  |  |
Gross realized gains | 20 | $ 0 | 73 | $ 0 |
Gross realized (losses) | 0 | 0 | (152) | 0 |
Net AFS realized gains (losses) | 20 | 0 | (79) | 0 |
Gains from calls on securities available for sale | 20 | 0 | 25 | 0 |
OTTI loss realized on debt investment | 0 | $ 0 | 0 | $ 0 |
Federal Agency [Member] |  |  |  |  |
Debt securities, available-for-sale [Abstract] |  |  |  |  |
Amortized cost | 29,998 |  | 29,998 |  | 84,982
Unrealized gains | 0 |  | 0 |  | 10
Unrealized losses | 167 |  | 167 |  | 693
Estimated fair value | 29,831 |  | 29,831 |  | 84,299
State & Municipal [Member] |  |  |  |  |
Debt securities, available-for-sale [Abstract] |  |  |  |  |
Amortized cost | 9 |  | 9 |  | 30,136
Unrealized gains | 0 |  | 0 |  | 16
Unrealized losses | 0 |  | 0 |  | 237
Estimated fair value | 9 |  | 9 |  | 29,915
Mortgage-Backed, Government Sponsored Enterprises [Member] |  |  |  |  |
Debt securities, available-for-sale [Abstract] |  |  |  |  |
Amortized cost | 433,393 |  | 433,393 |  | 493,225
Unrealized gains | 4,494 |  | 4,494 |  | 439
Unrealized losses | 292 |  | 292 |  | 10,354
Estimated fair value | 437,595 |  | 437,595 |  | 483,310
Mortgage-Backed, U.S. Government Agency Securities [Member] |  |  |  |  |
Debt securities, available-for-sale [Abstract] |  |  |  |  |
Amortized cost | 44,912 |  | 44,912 |  | 29,190
Unrealized gains | 1,021 |  | 1,021 |  | 270
Unrealized losses | 18 |  | 18 |  | 475
Estimated fair value | 45,915 |  | 45,915 |  | 28,985
Collateralized Mortgage Obligations, Government-Sponsored Enterprises [Member] |  |  |  |  |
Debt securities, available-for-sale [Abstract] |  |  |  |  |
Amortized cost | 343,682 |  | 343,682 |  | 332,409
Unrealized gains | 2,484 |  | 2,484 |  | 344
Unrealized losses | 456 |  | 456 |  | 7,211
Estimated fair value | 345,710 |  | 345,710 |  | 325,542
Collateralized Mortgage Obligations, U.S. Government Agency Securities [Member] |  |  |  |  |
Debt securities, available-for-sale [Abstract] |  |  |  |  |
Amortized cost | 72,443 |  | 72,443 |  | 47,684
Unrealized gains | 887 |  | 887 |  | 137
Unrealized losses | 217 |  | 217 |  | 1,376
Estimated fair value | $ 73,113 |  | $ 73,113 |  | $ 46,445

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- Definition Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27161-111563 + Details
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- Definition Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27161-111563 + Details
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