Investments (Schedule of Unrealized Loss of Securities) (Details) $ in Thousands	Jun. 30, 2023 USD ($) security	Dec. 31, 2022 USD ($) security
Fixed Maturities
Estimated Fair Value, Total	$ 1,312,526	$ 1,120,411
Gross Unrealized Loss, Total	$ (66,635)	$ (58,650)
Number of Securities, Total | security	551	568
U.S. government obligations
Estimated Fair Value, Less than 12 months		$ 1,135
Gross Unrealized Loss, Less than 12 months		$ (70)
Number of Securities, Less than 12 months | security		13
Estimated Fair value, Greater than 12 months	$ 1,146	$ 126
Gross Unrealized Loss, Greater than 12 months	$ (68)	$ (11)
Number of Securities, Greater than 12 months | security	9	5
Mortgage-back securities
Estimated Fair Value, Less than 12 months	$ 233,146	$ 233,624
Gross Unrealized Loss, Less than 12 months	$ (12,202)	$ (18,464)
Number of Securities, Less than 12 months | security	93	89
Estimated Fair value, Greater than 12 months	$ 87,683	$ 17,985
Gross Unrealized Loss, Greater than 12 months	$ (20,275)	$ (4,044)
Number of Securities, Greater than 12 months | security	57	14
Asset-backed securities
Estimated Fair Value, Less than 12 months	$ 14,234	$ 24,552
Gross Unrealized Loss, Less than 12 months	$ (1,386)	$ (3,278)
Number of Securities, Less than 12 months | security	10	23
Estimated Fair value, Greater than 12 months	$ 22,814	$ 5,321
Gross Unrealized Loss, Greater than 12 months	$ (2,599)	$ (711)
Number of Securities, Greater than 12 months | security	23	7
Collateralized loan obligation
Estimated Fair Value, Less than 12 months	$ 76,097	$ 203,549
Gross Unrealized Loss, Less than 12 months	$ (2,786)	$ (16,730)
Number of Securities, Less than 12 months | security	52	252
Estimated Fair value, Greater than 12 months	$ 162,126	$ 37,814
Gross Unrealized Loss, Greater than 12 months	$ (17,699)	$ (5,194)
Number of Securities, Greater than 12 months | security	240	47
States and Political Subdivisions - general obligations
Estimated Fair Value, Less than 12 months	$ 125	$ 101
Gross Unrealized Loss, Less than 12 months	$ (3)	$ (3)
Number of Securities, Less than 12 months | security	2	1
States and Political Subdivisions - special revenue
Estimated Fair Value, Less than 12 months		$ 47
Gross Unrealized Loss, Less than 12 months		$ (2)
Number of Securities, Less than 12 months | security		3
Estimated Fair value, Greater than 12 months		$ 158
Gross Unrealized Loss, Greater than 12 months		$ (21)
Number of Securities, Greater than 12 months | security		7
Corporate
Estimated Fair Value, Less than 12 months	$ 17,722	$ 37,286
Gross Unrealized Loss, Less than 12 months	$ (1,010)	$ (5,426)
Number of Securities, Less than 12 months | security	16	64
Estimated Fair value, Greater than 12 months	$ 14,888	$ 376
Gross Unrealized Loss, Greater than 12 months	$ (3,660)	$ (89)
Number of Securities, Greater than 12 months | security	45	7
Term loans
Estimated Fair Value, Less than 12 months	$ 682,545	$ 558,337
Gross Unrealized Loss, Less than 12 months	$ (4,947)	$ (4,607)
Number of Securities, Less than 12 months | security	4	36