Investments (Available for sale equity investments) (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Marketable Securities [Abstract]
Amortized cost, equity investments	$ 35,829	$ 29,809
Estimated market value, equity investments	52,291	42,117
Common stocks [Member]
Marketable Securities [Abstract]
Amortized cost, equity investments	9,775	9,775
Estimated market value, equity investments	24,179	20,440
Non-redeemable preferred stocks [Member]
Marketable Securities [Abstract]
Amortized cost, equity investments	26,054	20,034
Estimated market value, equity investments	$ 28,112	$ 21,677