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	Jun. 30, 2024	Dec. 31, 2023
Level 1 [Member]
Financial Assets:
Cash and Cash Equivalents	$ 621,933	$ 588,321
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 [Member]
Financial Assets:
Cash and Cash Equivalents	0	0
Certificates of Deposit	115,316	54,856
Receivables	445,358	461,682
Contract Assets	64,003	90,876
Closely-held Equity Securities	0	0
Financial Liabilities:
Accounts Payable and Accrued Expenses	35,528	25,989
Payable to Employees and Related Parties	65,116	45,838
Notes Payable	354,173	360,252
Level 3 [Member]
Financial Assets:
Cash and Cash Equivalents	0	0
Certificates of Deposit	0	0
Receivables	0	0
Contract Assets	0	0
Closely-held Equity Securities	632	636
Financial Liabilities:
Accounts Payable and Accrued Expenses	0	0
Payable to Employees and Related Parties	0	0
Notes Payable	0	0
Carrying Amount [Member]
Financial Assets:
Cash and Cash Equivalents	621,933	588,321
Certificates of Deposit	115,316	54,856
Receivables	448,240	465,295
Contract Assets	64,236	91,246
Closely-held Equity Securities	632	636
Financial Liabilities:
Accounts Payable and Accrued Expenses	35,528	25,989
Payable to Employees and Related Parties	65,116	45,838
Notes Payable	373,941	373,885
Total [Member]
Financial Assets:
Cash and Cash Equivalents	621,933	588,321
Certificates of Deposit	115,316	54,856
Receivables	445,358	461,682
Contract Assets	64,003	90,876
Closely-held Equity Securities	632	636
Financial Liabilities:
Accounts Payable and Accrued Expenses	35,528	25,989
Payable to Employees and Related Parties	65,116	45,838
Notes Payable	$ 354,173	$ 360,252