Loans and Investments - Purchased Credit Deterioration and Troubled Debt Restructurings (Details) $ in Thousands	1 Months Ended		12 Months Ended
	Jun. 30, 2021 USD ($)	Aug. 31, 2020 USD ($)	Dec. 31, 2021 USD ($) loan	Dec. 31, 2020 USD ($) loan	Dec. 31, 2019 USD ($)	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Principal paydowns			$ 2,516,771	$ 1,243,694	$ 1,753,693
Purchase of loan			9,209,475	2,376,233	2,712,354
Allowance for credit losses			$ 113,241	$ 148,329	71,069
Proceeds from full satisfaction of loans	$ 95,000
Reversal of allowance for credit losses	7,500
Interest income from loans	$ 3,500
Troubled debt restructurings, number | loan			2	0
Interest reserve			$ 87,400	$ 78,300
Number of loans covered under interest reserve | loan			328	186
Aggregate UPB covered under interest reserve			$ 5,750,000	$ 3,600,000
Hotel Portfolio
Financing Receivable, Recorded Investment, Past Due [Line Items]
Allowance for credit losses			8	7,759
Hotel Portfolio | Forbearance agreement
Financing Receivable, Recorded Investment, Past Due [Line Items]
Fixed rate of interest (as a percent)	9.50%
Principal reduction					$ (10,000)
Pay rate (as a percent)					1.00%
Hotel Portfolio | Forbearance agreement | LIBOR
Financing Receivable, Recorded Investment, Past Due [Line Items]
Variable rate, spread (as a percent)					3.00%
LIBOR Floor rate					1.50%
Retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
Allowance for credit losses			5,819	$ 13,861
Retail | Loan modification agreement
Financing Receivable, Recorded Investment, Past Due [Line Items]
Maturity period (in years)				3 years
Percentage of interest foregone				2.00
Principal paydowns		$ 6,000
Principal reduction			(8,000)
Additional reserve deposit			4,600
Retail | Loan modification agreement | LIBOR
Financing Receivable, Recorded Investment, Past Due [Line Items]
Variable rate, spread (as a percent)				5.50%
LIBOR Floor rate				6.50%
Bridge Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Principal amount			$ 35,000
Fixed rate of interest (as a percent)						10.00%
Bridge Loans | Hotel Portfolio
Financing Receivable, Recorded Investment, Past Due [Line Items]
Principal amount					$ 110,000
Purchase of loan				$ 60,000	50,000
Allowance for credit losses				7,500
Loan discount				39,900
Total discount received					$ 20,100
Bridge Loans | Retail | Loan modification agreement
Financing Receivable, Recorded Investment, Past Due [Line Items]
Principal amount				$ 26,500
Bridge Loans | Retail | Loan modification agreement | LIBOR
Financing Receivable, Recorded Investment, Past Due [Line Items]
Variable rate, spread (as a percent)				6.00%
LIBOR Floor rate				2.375%
Mezzanine Loans | Retail | Loan modification agreement
Financing Receivable, Recorded Investment, Past Due [Line Items]
Principal amount				$ 6,100
Fixed rate of interest (as a percent)				12.00%