Loans Receivable, Net - Additional Information (Detail)	3 Months Ended	12 Months Ended							15 Months Ended
	Dec. 31, 2024 USD ($) loan	Dec. 31, 2024 USD ($)	Dec. 31, 2024 USD ($) loan	Dec. 31, 2024 USD ($) security_loan	Dec. 31, 2023 USD ($)	Dec. 31, 2023 USD ($) loan	Dec. 31, 2023 USD ($) security_loan	Dec. 31, 2022 USD ($)	Dec. 31, 2024 USD ($) loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted-average risk rating	3.0	3.0	3.0	3.0	3.0	3.0	3.0		3.0
Increase in net CECL reserve		$ 157,000,000
Increase (decrease) in CECL reserves		541,603,000			$ 250,799,000
Amount charged off		384,603,000
CECL reserve	$ 733,936,000	733,936,000	$ 733,936,000	$ 733,936,000	576,936,000	$ 576,936,000	$ 576,936,000	$ 326,137,000	$ 733,936,000
Number of loans			130	130		178	178
Interest and related income		1,769,043,000			2,037,621,000			1,338,954,000
Principal balance	19,047,518,000	19,047,518,000	$ 19,047,518,000	$ 19,047,518,000	23,787,012,000	$ 23,787,012,000	$ 23,787,012,000	25,017,880,000	19,047,518,000
Net book value	18,313,582,000	18,313,582,000	$ 18,313,582,000	18,313,582,000	23,210,076,000	23,210,076,000	23,210,076,000		18,313,582,000
Number of loan modifications | loan			7
Real estate owned, net	588,185,000	588,185,000	$ 588,185,000	588,185,000	0	0	0		588,185,000
Joint Venture
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan exposure	43,300,000	43,300,000	43,300,000	43,300,000	612,900,000	612,900,000	612,900,000		43,300,000
Real estate owned, net	32,400,000	32,400,000	$ 32,400,000	32,400,000	0	$ 0	0		32,400,000
5
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | loan			13			13
Principal balance	1,827,561,000	1,827,561,000	$ 1,827,561,000	1,827,561,000	1,877,279,000	$ 1,877,279,000	1,877,279,000		1,827,561,000
4
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | loan			20			15
Principal balance	2,707,104,000	2,707,104,000	$ 2,707,104,000	2,707,104,000	2,725,930,000	$ 2,725,930,000	2,725,930,000		2,707,104,000
3
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | loan			65			99
Principal balance	9,246,692,000	9,246,692,000	$ 9,246,692,000	9,246,692,000	12,277,518,000	$ 12,277,518,000	12,277,518,000		$ 9,246,692,000
Payment Deferral
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loan modifications | loan									2
Aggregate amortized cost basis of loans									$ 446,200,000
Percentage to aggregate loans receivable portfolio									2.30%
Extended Maturity, Modification One
Accounts, Notes, Loans and Financing Receivable [Line Items]
Extension term									10 months
Extended Maturity, Modification Two
Accounts, Notes, Loans and Financing Receivable [Line Items]
Extension term									9 months
Extended Maturity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loan modifications | loan									5
Aggregate amortized cost basis of loans									$ 509,800,000
Percentage to aggregate loans receivable portfolio									2.70%
Extended Maturity | 5
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loan modifications | loan			4
Extended Maturity | 4
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loan modifications | loan			1
Extended Maturity, Loan One
Accounts, Notes, Loans and Financing Receivable [Line Items]
Extension term									2 years 6 months
Extended Maturity, Loan Two
Accounts, Notes, Loans and Financing Receivable [Line Items]
Extension term									6 months
Exit fee percentage									3.00%
Increase (decrease) in rate									4.00%
Extended Maturity, Loan Three
Accounts, Notes, Loans and Financing Receivable [Line Items]
Extension term									2 years
Increase to loan commitment									$ 34,500,000
Fixed coupon rate									15.00%
Floating rate									2.50%
Extended Maturity, Loan Four
Accounts, Notes, Loans and Financing Receivable [Line Items]
Extension term									5 years
Proceeds from repayment of loan									$ 6,000,000
Extended Maturity, Loan Five
Accounts, Notes, Loans and Financing Receivable [Line Items]
Extension term									4 years 9 months 18 days
Increase (decrease) in rate									(0.10%)
Extended Maturity, Senior Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loan modifications | loan			3
Extended Maturity, Senior Loans | 4
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loan modifications | loan			2
Extended Maturity, Senior Loans | 3
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loan modifications | loan			1
Office
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | loan			41			54
Principal balance	7,386,333,000	7,386,333,000	$ 7,386,333,000	7,386,333,000	9,253,609,000	$ 9,253,609,000	9,253,609,000		$ 7,386,333,000
Number of loan modifications | loan			5
Hospitality
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | loan			16			23
Principal balance	2,768,374,000	2,768,374,000	$ 2,768,374,000	2,768,374,000	4,161,525,000	$ 4,161,525,000	4,161,525,000		2,768,374,000
Number of loan modifications | loan			1
Mixed Use Asset
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loan modifications | loan			1
Seventeen Loans | Impaired loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Cash proceeds	88,000,000
One Loan Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | loan			1
Net book value	195,000,000	195,000,000	$ 195,000,000	195,000,000					195,000,000
One Loan Past Due | Junior Loan Participation
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net book value	50,000,000	50,000,000	50,000,000	50,000,000					50,000,000
Impaired loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Increase (decrease) in CECL reserves		547,584,000			227,892,000
Amount charged off		384,603,000
CECL reserve	$ 580,651,000	580,651,000	$ 580,651,000	580,651,000	417,670,000	417,670,000	417,670,000	$ 189,778,000	580,651,000
Number of new loans impaired | loan	1		6
Number of loans | loan			13
Interest and related income	$ 3,000,000
Principal balance	1,827,561,000	1,827,561,000	$ 1,827,561,000	1,827,561,000	1,877,279,000	1,877,279,000	1,877,279,000		1,827,561,000
Impaired loans | 5
Accounts, Notes, Loans and Financing Receivable [Line Items]
Principal balance	1,827,561,000	1,827,561,000	1,827,561,000	1,827,561,000	1,877,279,000	1,877,279,000	1,877,279,000		1,827,561,000
Impaired loans | 4
Accounts, Notes, Loans and Financing Receivable [Line Items]
Principal balance	0	0	0	0	0	0	0		0
Impaired loans | 3
Accounts, Notes, Loans and Financing Receivable [Line Items]
Principal balance	0	0	$ 0	0	$ 0	$ 0	$ 0		0
Unfunded Loan Commitment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | loan			60
Unfunded Loan Commitment | Payment Deferral
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unfunded loan commitments	23,900,000	23,900,000	$ 23,900,000	23,900,000					23,900,000
Unfunded Loan Commitment | Extended Maturity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unfunded loan commitments	$ 28,600,000	$ 28,600,000	$ 28,600,000	$ 28,600,000					$ 28,600,000