Investments - Cost or Amortized Cost and Fair Value of Securities Available for Sale (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 1,179,059	$ 1,152,852
Allowance for Expected Credit Losses	(758)	(920)	$ (489)
Gross Unrealized Gains	382	278
Gross Unrealized Losses	(127,175)	(137,584)
Fair Value	1,051,508	1,014,626
U.S. government obligations and agencies
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	26,815	12,602
Allowance for Expected Credit Losses	0	0
Gross Unrealized Gains	2	0
Gross Unrealized Losses	(1,000)	(938)
Fair Value	25,817	11,664
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	791,001	788,737
Allowance for Expected Credit Losses	(609)	(729)
Gross Unrealized Gains	121	130
Gross Unrealized Losses	(84,529)	(93,077)
Fair Value	705,984	695,061
Mortgage-backed and asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	333,246	327,166
Allowance for Expected Credit Losses	0	0
Gross Unrealized Gains	258	148
Gross Unrealized Losses	(37,642)	(39,707)
Fair Value	295,862	287,607
Municipal bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	17,137	14,924
Allowance for Expected Credit Losses	(5)	(2)
Gross Unrealized Gains	1	0
Gross Unrealized Losses	(2,246)	(2,551)
Fair Value	14,887	12,371
Redeemable preferred stock
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	10,860	9,423
Allowance for Expected Credit Losses	(144)	(189)	$ (117)
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(1,758)	(1,311)
Fair Value	$ 8,958	$ 7,923