Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Details
Available-for-sale Securities, Gross Realized Gains (Losses), Sale Proceeds	$ 50,521	$ 127,942	$ 127,977	$ 159,436
Available-for-sale Securities, Gross Realized Gains	349	1,238	1,305	1,853
Available-for-sale Securities, Gross Realized Losses	$ 121	$ 164	$ 844	$ 181

This item represents the gross profit realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27357-111563

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- Definition

The total amount of proceeds received for the sale of securities, categorized neither as held-to-maturity nor trading securities, during the reporting period.

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- Definition

This item represents the gross loss realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

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