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Investments - Schedule of Available-for-sale Securities (Details) - USD ($) $ in Thousands | Jun. 30, 2019 | Dec. 31, 2018
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Debt Securities, Available-for-sale [Line Items] |  |
Amortized cost | $ 377,227 | $ 393,631
Gross unrealized gains | 5,853 | 829
Gross unrealized losses | (785) | (6,115)
Estimated fair value | 382,295 | 388,345
U.S. Treasury Securities [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized cost | 2,297 | 1,999
Gross unrealized gains | 13 |
Gross unrealized losses |  | (28)
Estimated fair value | 2,310 | 1,971
U.S. Federal Agency Obligations [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized cost | 6,516 | 10,370
Gross unrealized gains | 84 | 32
Gross unrealized losses | (2) | (41)
Estimated fair value | 6,598 | 10,361
Municipal Obligations, Tax Exempt [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized cost | 152,891 | 161,529
Gross unrealized gains | 2,573 | 353
Gross unrealized losses | (227) | (2,770)
Estimated fair value | 155,237 | 159,112
Municipal Obligations, Taxable [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized cost | 52,606 | 53,178
Gross unrealized gains | 1,170 | 180
Gross unrealized losses | (11) | (323)
Estimated fair value | 53,765 | 53,035
Agency Mortgage-backed Securities [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized cost | 156,939 | 158,765
Gross unrealized gains | 2,013 | 264
Gross unrealized losses | (545) | (2,953)
Estimated fair value | 158,407 | 156,076
Certificates of Deposit [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized cost | 5,978 | 7,790
Gross unrealized gains |  |
Gross unrealized losses |  |
Estimated fair value | $ 5,978 | $ 7,790

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- Definition Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading. + References No definition available. + Details
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- Definition Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as 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 investments in debt and equity securities classified as available-for-sale. + References No definition available. + Details
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- Definition This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any. + References No definition available. + Details
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