Summary of Significant Accounting Policies - Narrative (Details) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2022 USD ($) segment	Jun. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
New Accounting Pronouncements or Change in Accounting Principle
Provision for expected credit losses	$ 300	$ 4,700	$ 89	$ 6,300	$ 3,592
Guaranty liabilities	25,900		25,900		25,989	$ 29,581
Allowance for doubtful accounts, period increase	800	2,900	$ 4,600	4,100
Number of operating segments | segment			1
Revenues	755,351	$ 629,871	$ 1,433,599	1,133,851
Commercial mortgage origination, net
New Accounting Pronouncements or Change in Accounting Principle
Revenues			193,850	$ 151,035
Accounts Receivable
New Accounting Pronouncements or Change in Accounting Principle
Allowance for doubtful accounts	20,700		20,700		16,700
Loans Receivable
New Accounting Pronouncements or Change in Accounting Principle
Allowance for credit loss	$ 3,800		$ 3,800		$ 3,800