Interest rate of mortgage loan within investment in mortgage loan on real estate by entity with substantial portion of business acquiring and holding investment real estate or interest in real estate.

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Amount of investment in mortgage loan on real estate by entity with substantial portion of business acquiring and holding investment real estate or interest in real estate.

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Loans - Held for Investment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Investments in loans
Carrying Value	$ 18,480,919	$ 12,217,352
Face Amount	18,521,795	12,262,840
Credit loss allowances	(67,270)	(77,444)
Total net loans	18,413,649	12,139,908	$ 11,470,224	$ 9,794,254
Loans held for investment
Investments in loans
Carrying Value	15,604,119	11,164,517
Face Amount	15,706,124	11,230,344
Credit loss allowances	(67,270)	(77,444)
Loans held-for-sale
Investments in loans
Carrying Value	2,876,800	1,052,835
Face Amount	2,815,671	1,032,496
Total net loans	2,876,800	1,052,835	884,150	1,187,552
Commercial Portfolio Segment
Investments in loans
Carrying Value	13,496,798
Commercial Portfolio Segment \| Loans held for investment
Investments in loans
Carrying Value	13,496,798	9,653,560
Face Amount	13,574,079	9,703,608
Credit loss allowances	(46,600)	(69,611)
Total net loans	13,450,198	9,583,949	8,517,054	7,075,577
Infrastructure Portfolio Segment
Investments in loans
Carrying Value	2,048,096
Reclassification to held for investment	61,300	104,300
Reclassification to held-for-sale		174,600
Infrastructure Portfolio Segment \| Loans held for investment
Investments in loans
Carrying Value	2,048,096	1,420,273
Face Amount	$ 2,071,912	$ 1,439,940
Weighted Average Life	4 years 3 months 18 days	4 years 3 months 18 days
Credit loss allowances	$ (20,670)	$ (7,833)
Total net loans	$ 2,027,426	$ 1,412,440	1,397,448	1,456,779
Infrastructure Portfolio Segment \| Loans held for investment \| Weighted-average
Investments in loans
Weighted Average Coupon	4.40%	4.40%
Infrastructure Portfolio Segment \| Loans held-for-sale
Investments in loans
Carrying Value		$ 120,540
Face Amount		$ 120,900
Weighted Average Life		3 years 2 months 12 days
Infrastructure Portfolio Segment \| Loans held-for-sale \| Weighted-average
Investments in loans
Weighted Average Coupon		3.10%
Residential Portfolio Segment
Investments in loans
Weighted Average Life	29 years 4 months 24 days	27 years 10 months 24 days
Reclassification to held for investment	$ 94,200
Reclassification to held-for-sale	125,400	$ 575,300
Residential Portfolio Segment \| Loans held for investment
Investments in loans
Total net loans	59,225	90,684	$ 671,572	$ 0
RMBS, fair value option \| Loans held-for-sale
Investments in loans
Carrying Value	2,590,005	841,963
Face Amount	$ 2,525,910	$ 820,807
RMBS, fair value option \| Loans held-for-sale \| Weighted-average
Investments in loans
Weighted Average Coupon	4.20%	6.00%
CMBS, fair value option \| Loans held-for-sale
Investments in loans
Carrying Value	$ 286,795	$ 90,332
Face Amount	$ 289,761	$ 90,789
Weighted Average Life	9 years	10 years
CMBS, fair value option \| Loans held-for-sale \| Weighted-average
Investments in loans
Weighted Average Coupon	4.00%	3.90%
First mortgage loan participation \| Loans held for investment
Investments in loans
Carrying Value	$ 12,991,099	$ 8,931,772
Face Amount	$ 13,067,524	$ 8,978,373
Weighted Average Life	1 year 10 months 24 days	1 year 6 months
First mortgage loan participation \| Loans held for investment \| Weighted-average
Investments in loans
Weighted Average Coupon	4.60%	5.30%
Subordinated mortgages \| Loans held for investment
Investments in loans
Carrying Value	$ 70,771	$ 71,185
Face Amount	$ 72,371	$ 72,257
Weighted Average Life	2 years 9 months 18 days	2 years 9 months 18 days
Subordinated mortgages \| Loans held for investment \| Weighted-average
Investments in loans
Weighted Average Coupon	9.80%	8.80%
Mezzanine Loans
Investments in loans
Total net loans	$ 1,400,000	$ 877,300
Mezzanine Loans \| Loans held for investment
Investments in loans
Carrying Value	417,504	620,319
Face Amount	$ 415,155	$ 619,352
Weighted Average Life	1 year 4 months 24 days	1 year 7 months 6 days
Mezzanine Loans \| Loans held for investment \| Weighted-average
Investments in loans
Weighted Average Coupon	9.40%	10.10%
Other \| Loans held for investment
Investments in loans
Carrying Value	$ 17,424	$ 30,284
Face Amount	$ 19,029	$ 33,626
Weighted Average Life	2 years 1 month 6 days	1 year 9 months 18 days
Other \| Loans held for investment \| Weighted-average
Investments in loans
Weighted Average Coupon	8.20%	8.90%
Residential loans, fair value option \| Loans held for investment
Investments in loans
Carrying Value	$ 59,225	$ 90,684
Face Amount	$ 60,133	$ 86,796
Residential loans, fair value option \| Loans held for investment \| Weighted-average
Investments in loans
Weighted Average Coupon	6.00%	6.00%
Residential loans, fair value option \| Residential Portfolio Segment \| Loans held for investment
Investments in loans
Carrying Value	$ 59,225