Investments (Equity Securities) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Debt and Equity Securities, FV-NI [Line Items]
Equity security	$ 20,698		$ 20,698		$ 16,033
Realized investment gains (losses), net	1,448	$ (2,869)	142	$ 3,092
Stock Mutual Funds [Member]
Debt and Equity Securities, FV-NI [Line Items]
Equity security	2,796		2,796		3,274
Bond Mutual Funds [Member]
Debt and Equity Securities, FV-NI [Line Items]
Equity security	11,810		11,810		12,311
Common stock [Member]
Debt and Equity Securities, FV-NI [Line Items]
Equity security	1,064		1,064		134
Non-redeemable Preferred Stock [Member]
Debt and Equity Securities, FV-NI [Line Items]
Equity security	5,028		5,028		$ 314
Equity Securities [Member]
Debt and Equity Securities, FV-NI [Line Items]
Realized investment gains (losses), net	$ 1,300	$ 200	$ 200	$ 800