Investments, Securities with Continuous Unrealized Loss Position (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Available-for-sale securities, continuous unrealized loss position, Fair Value [Abstract]
Less than 12 months	$ 29,783	$ 49,633
12 months or longer	6,037	125,778
Total	35,820	175,411
Available-for-sale securities, continuous unrealized loss position, Unrealized Losses [Abstract]
Less than 12 months	220	1,592
12 months or longer	127	10,259
Total	347	11,851
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	3,432	0
12 months or longer	3,533	24,786
Total	6,965	24,786
Available-for-sale securities, continuous unrealized loss position, Unrealized Losses [Abstract]
Less than 12 months	22	0
12 months or longer	31	1,061
Total	53	1,061
Obligations of States and Political Subdivisions [Member]
Available-for-sale securities, continuous unrealized loss position, Fair Value [Abstract]
Less than 12 months	3,106	0
12 months or longer	0	3,980
Total	3,106	3,980
Available-for-sale securities, continuous unrealized loss position, Unrealized Losses [Abstract]
Less than 12 months	53	0
12 months or longer	0	72
Total	53	72
Corporate Securities [Member]
Available-for-sale securities, continuous unrealized loss position, Fair Value [Abstract]
Less than 12 months	23,245	49,633
12 months or longer	2,504	97,012
Total	25,749	146,645
Available-for-sale securities, continuous unrealized loss position, Unrealized Losses [Abstract]
Less than 12 months	145	1,592
12 months or longer	96	9,126
Total	$ 241	$ 10,718