Debt and Preferred Equity Investments - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Aggregate weighted average current yield (as a percent)	7.87%
Debt Investments Held [Abstract]
Carrying Value	$ 1,783,336	$ 1,580,306
Mezzanine Loan with an Initial Maturity Date of June 2024
Debt Investments Held [Abstract]
Amount participated out	12,000
Mortgage/Mezzanine Loan With An Initial Maturity Due April 2021
Debt Investments Held [Abstract]
Amount participated out	96,400
Mezzanine Loan Due March 2022
Debt Investments Held [Abstract]
Amount participated out	400
Debt Investments in Mortgage Loans
Debt Investments Held [Abstract]
Future Funding Obligations	184,776
Senior Financing	5,607,560
Allowance for loan loss	(22,326)	0
Carrying Value	1,415,644	1,341,070
Total fixed rate
Debt Investments Held [Abstract]
Future Funding Obligations	10,000
Senior Financing	3,107,231
Carrying Value	603,999	499,410
Total fixed rate | Mortgage And Mezzanine Loan With An Initial Maturity Date Of October 2020
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	63,908
Carrying Value	55,798	55,573
Total fixed rate | Mezzanine Loan With Initial Maturity Date Of January 2021
Debt Investments Held [Abstract]
Future Funding Obligations	10,000
Senior Financing	0
Carrying Value	99,110	0
Total fixed rate | Mezzanine Loan, September 2021
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	15,000
Carrying Value	3,500	3,500
Total fixed rate | Mezzanine Loan with an Initial Maturity Date of April 2022
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	147,000
Carrying Value	24,957	24,952
Total fixed rate | Mezzanine Loan With An Initial Maturity Of August 2022
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	280,000
Carrying Value	39,296	38,734
Total fixed rate | Mezzanine Loan With Maturity June 2023
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	330,204
Carrying Value	220,420	215,737
Total fixed rate | Mezzanine Loan, with an Initial Maturity Date of November 2023
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	83,369
Carrying Value	12,716	12,714
Total fixed rate | Mezzanine Loan With An Initial Maturity Date Of December 2023
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	180,000
Carrying Value	30,000	30,000
Total fixed rate | Mezzanine Loan with an Initial Maturity Date of June 2024
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	115,000
Carrying Value	12,952	12,950
Total fixed rate | Mezzanine Loan, with an Initial Maturity Date of January 2025
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	95,000
Carrying Value	30,000	30,000
Total fixed rate | Mezzanine Loan with an Initial Maturity Date of June 2027
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	1,712,750
Carrying Value	55,250	55,250
Total fixed rate | Mezzanine Loan With Initial Maturity Date Of December 2029
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	85,000
Carrying Value	20,000	20,000
Total floating rate
Debt Investments Held [Abstract]
Future Funding Obligations	174,776
Senior Financing	2,500,329
Carrying Value	833,971	841,660
Total floating rate | Mortgage/Mezzanine Loan Due March 2020
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	0
Carrying Value	70,000	69,839
Total floating rate | Mortgage and Mezzanine Loan with an Initial Maturity Date of April 2020
Debt Investments Held [Abstract]
Future Funding Obligations	1,618
Senior Financing	29,053
Carrying Value	71,964	82,696
Total floating rate | Junior Mortgage Loan With An Initial Maturity April 2020
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	40,000
Carrying Value	20,000	20,000
Total floating rate | Mortgage/Mezzanine Loan Due August 2020
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	0
Carrying Value	19,983	19,971
Total floating rate | Mezzanine Loan Due September 2020
Debt Investments Held [Abstract]
Future Funding Obligations	32,972
Senior Financing	0
Carrying Value	118,378	106,473
Total floating rate | Mezzanine Loan With An Initial Maturity Date Of December 2021
Debt Investments Held [Abstract]
Future Funding Obligations	17,376
Senior Financing	436,763
Carrying Value	53,329	51,387
Total floating rate | Mortgage/Mezzanine Loan With An Initial Maturity Due April 2021
Debt Investments Held [Abstract]
Future Funding Obligations	9,429
Senior Financing	0
Carrying Value	96,880	96,570
Total floating rate | Mezzanine Loan With An Initial Maturity Due April 2021
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	275,000
Carrying Value	49,845	49,809
Total floating rate | Jr Mortgage Participation/Mezzanine Loan with an Initial Maturity of July 2021
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	60,000
Carrying Value	15,706	15,698
Total floating rate | Mezzanine Loan With An Initial Maturity Due July 2021
Debt Investments Held [Abstract]
Future Funding Obligations	11,459
Senior Financing	156,759
Carrying Value	42,985	41,395
Total floating rate | Mezzanine Loan Due July 2021, 2
Debt Investments Held [Abstract]
Future Funding Obligations	8,427
Senior Financing	49,616
Carrying Value	20,595	15,743
Total floating rate | Mezzanine Loan Due March 2022
Debt Investments Held [Abstract]
Future Funding Obligations	0
Senior Financing	1,115,000
Carrying Value	123,419	222,775
Total floating rate | Mortgage/Mezzanine Loan Due May 2022
Debt Investments Held [Abstract]
Future Funding Obligations	7,795
Senior Financing	0
Carrying Value	59,597	35,386
Total floating rate | Mezzanine Loan Due December 2022
Debt Investments Held [Abstract]
Future Funding Obligations	44,000
Senior Financing	0
Carrying Value	13,941	13,918
Total floating rate | Mortgage Loan Due February 2023
Debt Investments Held [Abstract]
Future Funding Obligations	41,700
Senior Financing	338,138
Carrying Value	$ 57,349	$ 0