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Accumulated Other Comprehensive Income (Changes in AOCI by Component) (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended |
--- | --- | --- | ---
Jun. 30, 2018 | Jun. 30, 2017 | Jun. 30, 2018 | Jun. 30, 2017 | Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Roll Forward] |  |  |  |  |  |
Beginning balance |  | $ (48,133) | $ (12,606) | $ (22,225) | $ (18,999) |
Other comprehensive loss before reclassifications | [1] | (7,845) | 6,033 | (33,893) | 12,339 |
Amounts reclassified from accumulated other comprehensive loss | [1] | 57 | 45 | 40 | 132 |
Net current-period other comprehensive income (loss) | [1] | (7,788) | 6,078 | (33,853) | 12,471 |
Ending balance |  | (55,921) | (6,528) | (55,921) | (6,528) |
Unrealized Gains and Losses on Available-for-Sale Securities [Member] |  |  |  |  |  |
Accumulated Other Comprehensive Income (Loss) [Roll Forward] |  |  |  |  |  |
Beginning balance |  | (45,748) | (11,002) | (19,779) | (12,704) |
Other comprehensive loss before reclassifications | [1] | (7,845) | 6,033 | (33,893) | 7,735 |
Amounts reclassified from accumulated other comprehensive loss | [1] | (4) | 0 | (82) | 0 |
Net current-period other comprehensive income (loss) | [1] | (7,849) | 6,033 | (33,975) | 7,735 |
Ending balance |  | (53,597) | (4,969) | (53,597) | (4,969) |
Unrealized Gains and Losses on Pension Plan Liability [Member] |  |  |  |  |  |
Accumulated Other Comprehensive Income (Loss) [Roll Forward] |  |  |  |  |  |
Beginning balance |  | (2,385) | (1,604) | (2,446) | (6,295) |
Other comprehensive loss before reclassifications | [1] | 0 | 0 | 0 | 4,604 |
Amounts reclassified from accumulated other comprehensive loss | [1] | 61 | 45 | 122 | 132 |
Net current-period other comprehensive income (loss) | [1] | 61 | 45 | 122 | 4,736 |
Ending balance |  | $ (2,324) | $ (1,559) | $ (2,324) | $ (1,559) |
Accounting Standards Update 2016-01 [Member] |  |  |  |  |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |  |  |  |
Cumulative Effect of New Accounting Principle in Period of Adoption |  |  |  |  |  | $ 0
Accounting Standards Update 2016-01 [Member] | Unrealized Gains and Losses on Available-for-Sale Securities [Member] |  |  |  |  |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |  |  |  |
Cumulative Effect of New Accounting Principle in Period of Adoption |  |  |  |  |  | 157
Accounting Standards Update 2016-01 [Member] | Unrealized Gains and Losses on Pension Plan Liability [Member] |  |  |  |  |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |  |  |  |
Cumulative Effect of New Accounting Principle in Period of Adoption |  |  |  |  |  | 0
Accounting Standards Update 2016-01 [Member] | Accumulated Other Comprehensive Income [Member] |  |  |  |  |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |  |  |  |
Cumulative Effect of New Accounting Principle in Period of Adoption |  |  |  |  |  | $ 157
[1] | All amounts are net of tax. Amounts in parenthesis indicate debits.

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- Definition Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=114867106&loc=d3e637-108580 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14A -URI http://asc.fasb.org/extlink&oid=114867106&loc=SL7669686-108580 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14 -URI http://asc.fasb.org/extlink&oid=114867106&loc=d3e681-108580 + Details
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