Fair Value Measurements - Carrying Amount and Estimated Fair Value of Financial Instrument Assets and Liabilities which are Not Measured at Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
US Treasury Securities | Cash and Cash Equivalents
Financial Assets:
Cash and Cash Equivalents(1)	$ 23,108	$ 9,967
Level 1
Financial Assets:
Cash and Cash Equivalents(1)	1,402,912	863,078
Certificates of Deposit	0	0
Receivables	0	0
Contract Assets	0	0
Closely-held Equity Securities	0	0
Financial Liabilities:
Accounts Payable and Accrued Expenses	0	0
Payable to Employees and Related Parties	0	0
Notes Payable	0	0
Level 2
Financial Assets:
Cash and Cash Equivalents(1)	0	0
Certificates of Deposit	40,421	66,660
Receivables	680,998	518,485
Contract Assets	173,097	76,184
Closely-held Equity Securities	0	0
Financial Liabilities:
Accounts Payable and Accrued Expenses	44,562	29,041
Payable to Employees and Related Parties	181,591	48,494
Notes Payable	575,879	356,531
Level 3
Financial Assets:
Cash and Cash Equivalents(1)	0	0
Certificates of Deposit	0	0
Receivables	0	0
Contract Assets	0	0
Closely-held Equity Securities	1,673	625
Financial Liabilities:
Accounts Payable and Accrued Expenses	0	0
Payable to Employees and Related Parties	0	0
Notes Payable	0	0
Carrying Amount
Financial Assets:
Cash and Cash Equivalents(1)	1,402,912	863,078
Certificates of Deposit	40,421	66,660
Receivables	685,665	522,816
Contract Assets	175,349	76,856
Closely-held Equity Securities	1,673	625
Financial Liabilities:
Accounts Payable and Accrued Expenses	44,562	29,041
Payable to Employees and Related Parties	181,591	48,494
Notes Payable	588,224	373,895
Total
Financial Assets:
Cash and Cash Equivalents(1)	1,402,912	863,078
Certificates of Deposit	40,421	66,660
Receivables	680,998	518,485
Contract Assets	173,097	76,184
Closely-held Equity Securities	1,673	625
Financial Liabilities:
Accounts Payable and Accrued Expenses	44,562	29,041
Payable to Employees and Related Parties	181,591	48,494
Notes Payable	$ 575,879	$ 356,531