Fair Value Measurements and Derivative Instruments (Recurring Basis) (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Estimated fair value	$ 157,979	$ 203,842
Fair Value, Recurring
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Money market funds	146,560	201,850
Equity securities	12,518	15,341
Mortgage-backed / asset-backed securities	98,464	119,901
Total assets	317,591	437,657
Fair Value, Recurring | Interest rate swaps
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative asset		8,425
Commingled fixed income securities
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Estimated fair value	1,612	1,581
Commingled fixed income securities | Fair Value, Recurring
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Estimated fair value	2,146	7,322
Government and related securities
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Estimated fair value	15,744	28,030
Government and related securities | Fair Value, Recurring
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Estimated fair value	15,744	30,488
Corporate debt securities
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Estimated fair value	42,159	54,330
Corporate debt securities | Fair Value, Recurring
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Estimated fair value	42,159	54,330
Level 1 | Fair Value, Recurring
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Money market funds	6,435	13,366
Equity securities	0	0
Mortgage-backed / asset-backed securities	0	0
Total assets	10,381	26,436
Level 1 | Fair Value, Recurring | Interest rate swaps
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative asset		0
Level 1 | Commingled fixed income securities | Fair Value, Recurring
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Estimated fair value	1,612	1,581
Level 1 | Government and related securities | Fair Value, Recurring
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Estimated fair value	2,334	11,489
Level 1 | Corporate debt securities | Fair Value, Recurring
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Estimated fair value	0	0
Level 2 | Fair Value, Recurring
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Money market funds	140,125	188,484
Equity securities	12,518	15,341
Mortgage-backed / asset-backed securities	98,464	119,901
Total assets	307,210	411,221
Level 2 | Fair Value, Recurring | Interest rate swaps
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative asset		8,425
Level 2 | Commingled fixed income securities | Fair Value, Recurring
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Estimated fair value	534	5,741
Level 2 | Government and related securities | Fair Value, Recurring
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Estimated fair value	13,410	18,999
Level 2 | Corporate debt securities | Fair Value, Recurring
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Estimated fair value	42,159	54,330
Level 3 | Fair Value, Recurring
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Money market funds	0	0
Equity securities	0	0
Mortgage-backed / asset-backed securities	0	0
Total assets	0	0
Level 3 | Fair Value, Recurring | Interest rate swaps
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative asset		0
Level 3 | Commingled fixed income securities | Fair Value, Recurring
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Estimated fair value	0	0
Level 3 | Government and related securities | Fair Value, Recurring
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Estimated fair value	0	0
Level 3 | Corporate debt securities | Fair Value, Recurring
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Estimated fair value	$ 0	$ 0