Segment Reporting - Summary of Financial Results by Segment (Detail) - USD ($) $ in Thousands	3 Months Ended									10 Months Ended	12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Dec. 31, 2016	Dec. 31, 2018	Dec. 31, 2017
Revenues:
Total revenues	$ 261,186	$ 200,162	$ 152,226	$ 109,684	$ 78,245	$ 48,904	$ 28,339	$ 2,444			$ 723,258	$ 157,932
Expenses:
Total expenses											340,341	71,532
Income from real estate-related securities											55,323	17,749
Segment net operating income											438,240	104,149
Depreciation and amortization										$ 0	406,295	121,793
Other income (expense):
General and administrative										(115)	(10,982)	(7,692)
Management fees										0	(42,659)	(8,867)
Performance participation allocation										0	(37,484)	(16,974)
Interest income											410	454
Interest expense											(233,184)	(36,884)
Other income (expense)											489	57
Net loss	(131,120)	(58,763)	(51,944)	(49,638)	(37,735)	(31,847)	(16,701)	(1,267)	$ (115)	(115)	(291,465)	(87,550)
Net loss attributable to non-controlling interests in third party joint ventures											6,188	1,292
Net loss attributable to non-controlling interests in BREIT OP											4,221
Net loss attributable to BREIT stockholders	$ (125,359)	$ (57,667)	$ (50,482)	$ (47,548)	$ (36,565)	$ (31,725)	$ (16,701)	$ (1,267)	$ (115)	$ (115)	(281,056)	(86,258)
Rental Property [Member]
Revenues:
Total revenues											494,519	110,429
Expenses:
Total expenses											243,093	51,115
Tenant Reimbursement Income [Member]
Revenues:
Total revenues											64,145	10,952
Hotel [Member]
Revenues:
Total revenues											138,433	29,916
Expenses:
Total expenses											97,248	20,417
Other Revenue [Member]
Revenues:
Total revenues											26,161	6,635
Multifamily [Member]
Revenues:
Total revenues											368,564	92,911
Expenses:
Total expenses											176,800	40,831
Segment net operating income											191,764	52,080
Depreciation and amortization											257,201	96,732
Multifamily [Member] | Rental Property [Member]
Revenues:
Total revenues											328,476	82,846
Expenses:
Total expenses											176,800	40,831
Multifamily [Member] | Tenant Reimbursement Income [Member]
Revenues:
Total revenues											17,143	3,476
Multifamily [Member] | Other Revenue [Member]
Revenues:
Total revenues											22,945	6,589
Industrial [Member]
Revenues:
Total revenues											203,662	30,858
Expenses:
Total expenses											62,824	9,265
Segment net operating income											140,838	21,593
Depreciation and amortization											116,206	17,063
Industrial [Member] | Rental Property [Member]
Revenues:
Total revenues											157,970	24,034
Expenses:
Total expenses											62,824	9,265
Industrial [Member] | Tenant Reimbursement Income [Member]
Revenues:
Total revenues											45,114	6,812
Industrial [Member] | Other Revenue [Member]
Revenues:
Total revenues											578	12
Hotel [Member]
Revenues:
Total revenues											140,918	29,916
Expenses:
Total expenses											97,248	20,417
Segment net operating income											43,670	9,499
Depreciation and amortization											27,944	6,071
Hotel [Member] | Hotel [Member]
Revenues:
Total revenues											138,433	29,916
Expenses:
Total expenses											97,248	20,417
Hotel [Member] | Other Revenue [Member]
Revenues:
Total revenues											2,485
Retail [Member]
Revenues:
Total revenues											10,114	4,247
Expenses:
Total expenses											3,469	1,019
Segment net operating income											6,645	3,228
Depreciation and amortization											4,944	1,927
Retail [Member] | Rental Property [Member]
Revenues:
Total revenues											8,073	3,549
Expenses:
Total expenses											3,469	1,019
Retail [Member] | Tenant Reimbursement Income [Member]
Revenues:
Total revenues											1,888	664
Retail [Member] | Other Revenue [Member]
Revenues:
Total revenues											153	34
Real Estate-Related Securities [Member]
Expenses:
Income from real estate-related securities											55,323	17,749
Segment net operating income											$ 55,323	$ 17,749