Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]: Debt Securities, Available-for-sale [Table Text Block] (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale, Amortized Cost	$ 459,587	$ 463,985
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	3,255	1,055
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	6,582	11,576
Debt Securities, Available-for-sale	456,260	453,464
Corporate Debt Securities
Debt Securities, Available-for-sale, Amortized Cost	219,136	202,194
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	2,377	701
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	3,406	5,406
Debt Securities, Available-for-sale	218,107	197,489
Collateralized Mortgage Backed Securities
Debt Securities, Available-for-sale, Amortized Cost	5,942	6,092
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	0	0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	149	252
Debt Securities, Available-for-sale	5,793	5,840
US Treasury Securities
Debt Securities, Available-for-sale, Amortized Cost	44,440	63,231
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	93	1
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	250	423
Debt Securities, Available-for-sale	44,283	62,809
US Government Agencies Debt Securities
Debt Securities, Available-for-sale, Amortized Cost	1	3
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	0	0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	0	0
Debt Securities, Available-for-sale	1	3
US Government-sponsored Enterprises Debt Securities
Debt Securities, Available-for-sale, Amortized Cost	6,505	6,596
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	0	0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	110	110
Debt Securities, Available-for-sale	6,395	6,486
US States and Political Subdivisions Debt Securities
Debt Securities, Available-for-sale, Amortized Cost	170,633	172,860
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	623	302
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	2,639	5,228
Debt Securities, Available-for-sale	168,617	167,934
Debt Security, Government, Non-US
Debt Securities, Available-for-sale, Amortized Cost	6,960	7,039
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	88	51
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	28	46
Debt Securities, Available-for-sale	7,020	7,044
Redeemable Preferred Stock
Debt Securities, Available-for-sale, Amortized Cost	5,970	5,970
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	74	0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	0	111
Debt Securities, Available-for-sale	$ 6,044	$ 5,859

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).

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=82897076&loc=d3e27161-111563

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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).

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-Topic 320
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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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-Section 50
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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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