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, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale, Amortized Cost	$ 412,589	$ 383,425
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	5,430	3,827
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	4,015	2,278
Debt Securities, Available-for-sale	414,004	384,974
Corporate Debt Securities
Debt Securities, Available-for-sale, Amortized Cost	139,487	161,369
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	1,476	1,832
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	2,993	1,178
Debt Securities, Available-for-sale	137,970	162,023
Collateralized Mortgage Backed Securities
Debt Securities, Available-for-sale, Amortized Cost	5,143	5,328
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	223	54
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	0	0
Debt Securities, Available-for-sale	5,366	5,382
US Treasury Securities
Debt Securities, Available-for-sale, Amortized Cost	50,348	50,340
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	1,175	257
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	0	48
Debt Securities, Available-for-sale	51,523	50,549
US Government-sponsored Enterprises Debt Securities
Debt Securities, Available-for-sale, Amortized Cost	6,137	6,230
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	1	0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	271	107
Debt Securities, Available-for-sale	5,867	6,123
US States and Political Subdivisions Debt Securities
Debt Securities, Available-for-sale, Amortized Cost	204,836	153,439
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	2,252	1,512
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	751	943
Debt Securities, Available-for-sale	206,337	154,008
Debt Security, Government, Non-US
Debt Securities, Available-for-sale, Amortized Cost	6,638	6,719
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	303	172
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	0	2
Debt Securities, Available-for-sale	$ 6,941	$ 6,889

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)
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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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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
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