Investments, Securities with Continuous Unrealized Loss Position (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($) Securities	Dec. 31, 2020 USD ($) Securities
Available-for-sale securities, continuous unrealized loss position, Fair Value [Abstract]
Less than 12 months	$ 33,467	$ 11,647
12 months or longer	4,761	0
Total	38,228	11,647
Available-for-sale securities, continuous unrealized loss position, Unrealized Losses [Abstract]
Less than 12 months	465	94
12 months or longer	252	0
Total	717	94
Gross OTTI losses charged to realized gains	$ 0	$ 0
Number of securities in unrealized loss position | Securities	61	20
U.S. Treasury Securities and Obligations of U.S. Government Agencies and Authorities [Member]
Available-for-sale securities, continuous unrealized loss position, Fair Value [Abstract]
Less than 12 months	$ 30,141	$ 7,045
12 months or longer	0	0
Total	30,141	7,045
Available-for-sale securities, continuous unrealized loss position, Unrealized Losses [Abstract]
Less than 12 months	416	26
12 months or longer	0	0
Total	416	26
Corporate Securities [Member]
Available-for-sale securities, continuous unrealized loss position, Fair Value [Abstract]
Less than 12 months	3,326	4,602
12 months or longer	4,761	0
Total	8,087	4,602
Available-for-sale securities, continuous unrealized loss position, Unrealized Losses [Abstract]
Less than 12 months	49	68
12 months or longer	252	0
Total	$ 301	$ 68