Fair Value Measurements - Fair Values of Financial Assets and Liabilities, Including Derivative Financial Instruments (Details) $ in Thousands	Mar. 31, 2025 USD ($)	Dec. 31, 2024 USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Estimated Fair Value	$ 1,656,977	$ 1,933,226
Trading investments	53,732	$ 53,262
Level 3  | Valuation Technique, Discounted Cash Flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Estimated Fair Value	2,472
Trading investments	51,296
Total	$ 53,768
Level 3  | Valuation Technique, Discounted Cash Flow | Minimum | Measurement Input, Prepayment Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities	0.069
Residual Interests	0.069
Level 3  | Valuation Technique, Discounted Cash Flow | Minimum | Measurement Input, Default Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities	0.040
Residual Interests	0.040
Level 3  | Valuation Technique, Discounted Cash Flow | Maximum | Measurement Input, Prepayment Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities	0.110
Residual Interests	0.110
Level 3  | Valuation Technique, Discounted Cash Flow | Maximum | Measurement Input, Default Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities	0.170
Residual Interests	0.170
Level 3  | Valuation Technique, Discounted Cash Flow | Weighted Average | Measurement Input, Prepayment Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities	0.083
Residual Interests	0.083
Level 3  | Valuation Technique, Discounted Cash Flow | Weighted Average | Measurement Input, Default Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities	0.115
Residual Interests	0.115