Fair Value Measurement - Summary of Carrying Amounts, Estimated Fair Values, and Valuation Input Levels of Certain Financial Instruments (Details) $ in Thousands	Jun. 30, 2021 USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value	$ 27,351
Mutual Funds - Corporate & Government Debt
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value	19,985
ETFs - Corporate & Government Debt
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value	7,366
Carrying Amount
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value	27,351
Carrying Amount | Mutual Funds - Corporate & Government Debt | Corporate & Government Debt
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value	19,985
Carrying Amount | ETFs - Corporate & Government Debt | Corporate & Government Debt
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value	7,366
Fair Value
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value	27,351
Fair Value | Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value	27,351
Fair Value | Mutual Funds - Corporate & Government Debt | Corporate & Government Debt
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value	19,985
Fair Value | Mutual Funds - Corporate & Government Debt | Level 1 | Corporate & Government Debt
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value	19,985
Fair Value | ETFs - Corporate & Government Debt | Corporate & Government Debt
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value	7,366
Fair Value | ETFs - Corporate & Government Debt | Level 1 | Corporate & Government Debt
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value	$ 7,366