Investments Allowance for Expected Credit Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Marketable Securities
Balance, beginning of period	$ 1,054
Credit losses on securities with no previously recorded credit losses	9	$ 1,054
Net increases (decreases) in allowance on previously impaired securities	(137)
Reduction due to sales	(235)
Balance, end of period	691	1,054
Debt Securities, Available-for-sale, Allowance for Credit Loss [Abstract]
Decrease in allowance for expected credit losses	691	1,054
Corporate and other securities
Marketable Securities
Balance, beginning of period	1,054
Balance, end of period	$ 691	$ 1,054