Fair Value Disclosures [Text Block]: Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Beginning Balance	$ 1,481	$ 1,664	$ 1,529	$ 1,709
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)	(6)	(6)	(12)	(14)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	(42)	(38)	(84)	(75)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Ending Balance	1,433	1,620	1,433	1,620
Gain (Loss) on Investments
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings	0		0	0
US States and Political Subdivisions Debt Securities
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Beginning Balance	1,481	1,664	1,529	1,709
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)	(6)	(6)	(12)	(14)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	(42)	(38)	(84)	(75)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Ending Balance	1,433	$ 1,620	1,433	1,620
US States and Political Subdivisions Debt Securities | Gain (Loss) on Investments
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings	$ 0		$ 0	$ 0