Debt and Preferred Equity Investments - Narrative (Details)	12 Months Ended
	Dec. 31, 2021 USD ($) investment segment	Dec. 31, 2020 USD ($) segment investment	Dec. 31, 2019 USD ($)
Preferred equity investment
Number of investments, nonperforming | investment	2	1
Debt and preferred equity investments	$ 1,088,723,000	$ 1,076,542,000
Recorded investment, past due	1,088,723,000	1,076,542,000
Financing receivable, nonaccrual status	$ 27,700,000	$ 27,700,000
Number of portfolio segments of financial receivables (segment) | segment	1	1
Current period provision for loan loss	$ 0	$ 20,693,000	$ 0
Affiliated Entity
Preferred equity investment
Additional amount of financing receivables included in other assets	50,300,000	66,200,000
Current period provision for loan loss	2,900,000	14,600,000
ASC 326
Preferred equity investment
Adjustment upon adoption of ASC 326		11,400,000
3 - High Risk Assets - Loss more likely than not
Preferred equity investment
Recorded investment, past due	6,890,000	16,340,000
Financing Receivables, Equal to Greater than 90 Days Past Due
Preferred equity investment
Recorded investment, past due	0	0
Total floating rate
Preferred equity investment
Debt and preferred equity investments	294,970,000	352,460,000
Mortgage/Mezzanine Loan Due March 2020 | Total floating rate
Preferred equity investment
Debt and preferred equity investments	216,000,000	6,800,000
Preferred equity investments
Preferred equity investment
Debt and preferred equity investments	273,006,000	$ 259,786,000
Preferred equity investments | Preferred equity investments
Preferred equity investment
Debt and preferred equity investments	$ 6,800,000