Borrowings and Debt - Schedule of Long Term Debt (Details) - USD ($)	Mar. 31, 2025	Dec. 31, 2024	Aug. 29, 2024
Fair Value, Inputs, Level 2
Debt Instrument [Line Items]
Carrying Value	$ 274,400,000	$ 274,300,000
Fair Value	271,400,000	271,700,000
Line of Credit | Revolving credit facility | Fair Value, Inputs, Level 2
Debt Instrument [Line Items]
Carrying Value	80,000,000.0	0
Fair Value	80,000,000.0	0
Line of Credit | Revolving credit facility | The Acadian Credit Agreement
Debt Instrument [Line Items]
Face amount	140,000,000
Maximum borrowing capacity			$ 140,000,000
Line of Credit | Revolving credit facility | The Acadian Credit Agreement | Fair Value, Inputs, Level 2
Debt Instrument [Line Items]
Carrying Value	80,000,000.0	0
Fair Value	80,000,000.0	0
Line of Credit | Revolving credit facility | The Original Credit Agreement
Debt Instrument [Line Items]
Maximum borrowing capacity			$ 125,000,000
Senior notes | 4.80% Senior Notes Due July 27, 2026
Debt Instrument [Line Items]
Face amount	$ 275,000,000
Interest rate	4.80%
Senior notes | 4.80% Senior Notes Due July 27, 2026 | Fair Value, Inputs, Level 2
Debt Instrument [Line Items]
Carrying Value	$ 274,400,000	274,300,000
Fair Value	$ 271,400,000	$ 271,700,000