Fair Value Measurements (Available for Sale) (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost	$ 148,962	$ 143,084
Unrealized Gains	134	1,523
Unrealized Losses	(11,093)	(1,396)
Fair Value	138,003	143,211
Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 Months, Fair Value	112,893	83,656
Less than 12 Months, Unrealized Losses	(7,896)	(1,308)
12 Months or Greater, Fair Value	23,912	2,652
12 Months or Greater, Unrealized Losses	(3,197)	(88)
Total, Fair Value	136,805	86,308
Total, Unrealized Losses	(11,093)	(1,396)
Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Fair Value [Abstract]
Amortized Cost, Due within one year	20,553
Fair Value, Due within one year	20,333
Amortized Cost, Due after one year through five years	117,590
Fair Value, Due after one year through five years	108,498
Amortized Cost, Due after five years	10,819
Fair Value, Due after five years	9,172
Restricted investments:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost	86,490	84,011
Unrealized Gains	22	999
Unrealized Losses	(6,950)	(655)
Fair Value	79,562	84,355
Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 Months, Fair Value	55,380	37,170
Less than 12 Months, Unrealized Losses	(3,753)	(572)
12 Months or Greater, Fair Value	23,912	1,938
12 Months or Greater, Unrealized Losses	(3,197)	(83)
Total, Fair Value	79,292	39,108
Total, Unrealized Losses	(6,950)	(655)
Investments in lieu of retention:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost	62,472	59,073
Unrealized Gains	112	524
Unrealized Losses	(4,143)	(741)
Fair Value	58,441	58,856
Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 Months, Fair Value	57,513	46,486
Less than 12 Months, Unrealized Losses	(4,143)	(736)
12 Months or Greater, Fair Value	0	714
12 Months or Greater, Unrealized Losses	0	(5)
Total, Fair Value	57,513	47,200
Total, Unrealized Losses	(4,143)	(741)
Corporate debt securities | Restricted investments:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost	47,529	46,649
Unrealized Gains	22	438
Unrealized Losses	(3,866)	(438)
Fair Value	43,685	46,649
Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 Months, Fair Value	26,673	28,639
Less than 12 Months, Unrealized Losses	(1,817)	(434)
12 Months or Greater, Fair Value	16,742	207
12 Months or Greater, Unrealized Losses	(2,049)	(4)
Total, Fair Value	43,415	28,846
Total, Unrealized Losses	(3,866)	(438)
Corporate debt securities | Investments in lieu of retention:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost	61,656	58,261
Unrealized Gains	0	72
Unrealized Losses	(4,143)	(741)
Fair Value	57,513	57,592
U.S. government agency securities | Restricted investments:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost	29,063	28,316
Unrealized Gains	0	459
Unrealized Losses	(1,756)	(133)
Fair Value	27,307	28,642
Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 Months, Fair Value	22,552	5,382
Less than 12 Months, Unrealized Losses	(1,108)	(97)
12 Months or Greater, Fair Value	4,755	824
12 Months or Greater, Unrealized Losses	(648)	(36)
Total, Fair Value	27,307	6,206
Total, Unrealized Losses	(1,756)	(133)
Municipal bonds | Restricted investments:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost	9,334	8,475
Unrealized Gains	0	100
Unrealized Losses	(1,274)	(78)
Fair Value	8,060	8,497
Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 Months, Fair Value	6,037	2,714
Less than 12 Months, Unrealized Losses	(816)	(35)
12 Months or Greater, Fair Value	2,023	907
12 Months or Greater, Unrealized Losses	(458)	(43)
Total, Fair Value	8,060	3,621
Total, Unrealized Losses	(1,274)	(78)
Municipal bonds | Investments in lieu of retention:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost	816	812
Unrealized Gains	112	452
Unrealized Losses	0	0
Fair Value	928	1,264
Corporate certificates of deposit | Restricted investments:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized Cost	564	571
Unrealized Gains	0	2
Unrealized Losses	(54)	(6)
Fair Value	510	567
Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 Months, Fair Value	118	435
Less than 12 Months, Unrealized Losses	(12)	(6)
12 Months or Greater, Fair Value	392	0
12 Months or Greater, Unrealized Losses	(42)	0
Total, Fair Value	510	435
Total, Unrealized Losses	$ (54)	$ (6)