Financial Derivatives (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Derivative [Line Items]
Spread on written credit derivatives	2.27%
Written credit derivative spread threshold	20.00%	20.00%
Credit Default Swap, Selling Protection [Member]
Derivative [Line Items]
Credit risk derivative in excess of threshold, at fair value, net	$ (33)	$ (33)
Total net up-front payments received	$ 800	$ 800
Minimum
Derivative [Line Items]
Upfront points on written credit derivative in excess of threshold	46.3	46.3
Maximum
Derivative [Line Items]
Spread on written credit derivatives		3.10%
Upfront points on written credit derivative in excess of threshold	88.8	88.8