Accumulated Other Comprehensive Income (Loss) (Changes in AOCI by component) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	$ (2,990)	$ (8,656)	$ (7,685)	$ (2,602)
OCI before reclassifications	(4,749)	1,947	(10,622)	9,882
Tax effect	(992)	436	(2,170)	2,094
Unrealized gains (losses), net of tax	3,757	(1,511)	8,452	(7,788)
Cumulative Effect of New Accounting Principle in Period of Adoption		0		0
Ending Balance	767	(10,167)	767	(10,167)
ASU 2016-01 [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Cumulative Effect of New Accounting Principle in Period of Adoption	0	223	0	223
Unrealized Holding Gains (Losses) on AFS Securities [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(441)	(5,759)	(5,200)	391
OCI before reclassifications	(4,876)	1,978	(10,830)	10,035
Tax effect	(1,018)	442	(2,213)	2,126
Unrealized gains (losses), net of tax	3,858	(1,536)	8,617	(7,909)
Ending Balance	3,417	(7,295)	3,417	(7,295)
Unrealized Holding Gains (Losses) on AFS Securities [Member] \| ASU 2016-01 [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Cumulative Effect of New Accounting Principle in Period of Adoption	0	223	0	223
Defined Benefit Pension Plan [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(2,741)	(3,223)	(2,741)	(3,223)
OCI before reclassifications	0	0	0	0
Tax effect	0	0	0	0
Unrealized gains (losses), net of tax	0	0	0	0
Ending Balance	(2,741)	(3,223)	(2,741)	(3,223)
Defined Benefit Pension Plan [Member] \| ASU 2016-01 [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Cumulative Effect of New Accounting Principle in Period of Adoption	0	0	0	0
Gain (Loss) on Derivative Instruments [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	192	326	256	230
OCI before reclassifications	127	(31)	208	(153)
Tax effect	26	(6)	43	(32)
Unrealized gains (losses), net of tax	(101)	25	(165)	121
Ending Balance	91	351	91	351
Gain (Loss) on Derivative Instruments [Member] \| ASU 2016-01 [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Cumulative Effect of New Accounting Principle in Period of Adoption	0	0	0	0
Auction Rate Money Market Preferred Stocks [Member] \| Unrealized Holding Gains (Losses) on AFS Securities [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Unrealized gains (losses), net of tax	$ 30	$ 123	$ 295	$ 86

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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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.

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Amount after tax of increase (decrease) to equity or (increase) decrease to net assets, resulting from the cumulative effect adjustment of a new accounting principle applied in the period of adoption.

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Amount before tax and reclassification adjustments of other comprehensive income (loss).

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Amount after tax and reclassification adjustments of other comprehensive income (loss).

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Amount of tax expense (benefit) allocated to other comprehensive income (loss).

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