Debt - Components of Debt (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Outstanding Principal	$ 9,377,524	$ 9,172,842
Fixed Rate
Debt Instrument [Line Items]
Outstanding Principal	1,221,952	1,222,428
Variable Rate
Debt Instrument [Line Items]
Outstanding Principal	$ 8,155,572	7,950,414
5.375% Exchangeable Notes | Convertible and Exchangeable Senior Notes
Debt Instrument [Line Items]
Interest Rate (percentage)	5.375%
Recourse
Debt Instrument [Line Items]
Outstanding Principal	$ 1,330,171	931,294
Recourse | Fixed Rate
Debt Instrument [Line Items]
Outstanding Principal	650,054	651,177
Recourse | Variable Rate
Debt Instrument [Line Items]
Outstanding Principal	680,117	280,117
Recourse | Corporate credit facility
Debt Instrument [Line Items]
Outstanding Principal	$ 400,000	$ 0
Weighted Average Interest Rate (Per Annum) (percent)	2.69%
Weighted Average Years Remaining to Maturity	1 year 6 months	2 years
Recourse | Corporate credit facility | Fixed Rate
Debt Instrument [Line Items]
Outstanding Principal	$ 0	$ 0
Recourse | Corporate credit facility | Variable Rate
Debt Instrument [Line Items]
Outstanding Principal	$ 400,000	$ 0
Weighted Average Interest Rate (Per Annum) (percent)	2.69%
Weighted Average Years Remaining to Maturity	1 year 6 months	2 years
Recourse | Convertible and Exchangeable Senior Notes
Debt Instrument [Line Items]
Outstanding Principal	$ 616,105	$ 616,105
Weighted Average Interest Rate (Per Annum) (percent)	4.27%	4.27%
Weighted Average Years Remaining to Maturity	1 year 6 months	2 years
Recourse | Convertible and Exchangeable Senior Notes | Fixed Rate
Debt Instrument [Line Items]
Outstanding Principal	$ 616,105	$ 616,105
Weighted Average Interest Rate (Per Annum) (percent)	4.27%	4.27%
Weighted Average Years Remaining to Maturity	1 year 6 months	2 years
Recourse | Convertible and Exchangeable Senior Notes | Variable Rate
Debt Instrument [Line Items]
Outstanding Principal	$ 0	$ 0
Recourse | Secured debt
Debt Instrument [Line Items]
Outstanding Principal	$ 33,949	$ 35,072
Weighted Average Interest Rate (Per Annum) (percent)	5.02%	5.02%
Weighted Average Years Remaining to Maturity	5 years 4 months 24 days	5 years 10 months 24 days
Recourse | Secured debt | Fixed Rate
Debt Instrument [Line Items]
Outstanding Principal	$ 33,949	$ 35,072
Weighted Average Interest Rate (Per Annum) (percent)	5.02%	5.02%
Weighted Average Years Remaining to Maturity	5 years 4 months 24 days	5 years 10 months 24 days
Recourse | Secured debt | Variable Rate
Debt Instrument [Line Items]
Outstanding Principal	$ 0	$ 0
Recourse-NRF | Junior subordinated debt (2)
Debt Instrument [Line Items]
Outstanding Principal	$ 280,117	$ 280,117
Weighted Average Interest Rate (Per Annum) (percent)	3.17%	4.77%
Weighted Average Years Remaining to Maturity	15 years 10 months 24 days	16 years 4 months 24 days
Recourse-NRF | Junior subordinated debt (2) | Fixed Rate
Debt Instrument [Line Items]
Outstanding Principal	$ 0	$ 0
Recourse-NRF | Junior subordinated debt (2) | Variable Rate
Debt Instrument [Line Items]
Outstanding Principal	$ 280,117	$ 280,117
Weighted Average Interest Rate (Per Annum) (percent)	3.17%	4.77%
Weighted Average Years Remaining to Maturity	15 years 10 months 24 days	16 years 4 months 24 days
Non-recourse
Debt Instrument [Line Items]
Outstanding Principal	$ 8,047,353	$ 8,241,548
Non-recourse | Fixed Rate
Debt Instrument [Line Items]
Outstanding Principal	571,898	571,251
Non-recourse | Variable Rate
Debt Instrument [Line Items]
Outstanding Principal	7,475,455	7,670,297
Non-recourse | Secured debt | Digital
Debt Instrument [Line Items]
Outstanding Principal	$ 515,007	$ 539,155
Weighted Average Interest Rate (Per Annum) (percent)	5.47%	6.98%
Weighted Average Years Remaining to Maturity	4 years 4 months 24 days	4 years 9 months 18 days
Non-recourse | Secured debt | Healthcare Segment
Debt Instrument [Line Items]
Outstanding Principal	$ 2,922,442	$ 2,953,706
Weighted Average Interest Rate (Per Annum) (percent)	3.88%	5.13%
Weighted Average Years Remaining to Maturity	3 years 10 months 24 days	4 years 4 months 24 days
Non-recourse | Secured debt | Hospitality
Debt Instrument [Line Items]
Outstanding Principal	$ 2,667,374	$ 2,667,347
Weighted Average Interest Rate (Per Annum) (percent)	3.29%	4.87%
Weighted Average Years Remaining to Maturity	24 days	4 years 7 months 6 days
Non-recourse | Secured debt | Other Real Estate Equity Investments
Debt Instrument [Line Items]
Outstanding Principal	$ 1,722,234	$ 1,804,647
Weighted Average Interest Rate (Per Annum) (percent)	3.21%	4.09%
Weighted Average Years Remaining to Maturity	1 year 6 months	2 years 10 months 24 days
Non-recourse | Secured debt | Fixed Rate | Digital
Debt Instrument [Line Items]
Outstanding Principal	$ 0	$ 0
Non-recourse | Secured debt | Fixed Rate | Healthcare Segment
Debt Instrument [Line Items]
Outstanding Principal	$ 404,423	$ 405,980
Weighted Average Interest Rate (Per Annum) (percent)	4.55%	4.55%
Weighted Average Years Remaining to Maturity	4 years 7 months 6 days	5 years 1 month 6 days
Non-recourse | Secured debt | Fixed Rate | Hospitality
Debt Instrument [Line Items]
Outstanding Principal	$ 14,271	$ 13,494
Weighted Average Interest Rate (Per Annum) (percent)	12.74%	12.71%
Weighted Average Years Remaining to Maturity	3 days	1 year 7 months 6 days
Non-recourse | Secured debt | Fixed Rate | Other Real Estate Equity Investments
Debt Instrument [Line Items]
Outstanding Principal	$ 153,204	$ 151,777
Weighted Average Interest Rate (Per Annum) (percent)	4.23%	4.26%
Weighted Average Years Remaining to Maturity	2 years 9 months 18 days	3 years 4 months 24 days
Non-recourse | Secured debt | Variable Rate | Digital
Debt Instrument [Line Items]
Outstanding Principal	$ 515,007	$ 539,155
Weighted Average Interest Rate (Per Annum) (percent)	5.47%	6.98%
Weighted Average Years Remaining to Maturity	4 years 4 months 24 days	4 years 9 months 18 days
Non-recourse | Secured debt | Variable Rate | Healthcare Segment
Debt Instrument [Line Items]
Outstanding Principal	$ 2,518,019	$ 2,547,726
Weighted Average Interest Rate (Per Annum) (percent)	3.78%	5.22%
Weighted Average Years Remaining to Maturity	3 years 8 months 12 days	4 years 3 months 18 days
Non-recourse | Secured debt | Variable Rate | Hospitality
Debt Instrument [Line Items]
Outstanding Principal	$ 2,653,103	$ 2,653,853
Weighted Average Interest Rate (Per Annum) (percent)	3.23%	4.83%
Weighted Average Years Remaining to Maturity	24 days	4 years 7 months 6 days
Non-recourse | Secured debt | Variable Rate | Other Real Estate Equity Investments
Debt Instrument [Line Items]
Outstanding Principal	$ 1,569,030	$ 1,652,870
Weighted Average Interest Rate (Per Annum) (percent)	3.11%	4.08%
Weighted Average Years Remaining to Maturity	1 year 3 months 18 days	2 years 9 months 18 days
Non-recourse, real estate debt | Secured debt
Debt Instrument [Line Items]
Outstanding Principal	$ 220,296	$ 276,693
Weighted Average Interest Rate (Per Annum) (percent)	3.46%	3.72%
Weighted Average Years Remaining to Maturity	1 year 8 months 12 days	1 year 9 months 18 days
Non-recourse, real estate debt | Secured debt | Fixed Rate
Debt Instrument [Line Items]
Outstanding Principal	$ 0	$ 0
Non-recourse, real estate debt | Secured debt | Variable Rate
Debt Instrument [Line Items]
Outstanding Principal	$ 220,296	$ 276,693
Weighted Average Interest Rate (Per Annum) (percent)	3.46%	3.72%
Weighted Average Years Remaining to Maturity	1 year 8 months 12 days	1 year 9 months 18 days