Segment Reporting - Summary of Financial Results by Segment (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues:
Total revenues	$ 438,033	$ 200,162	$ 1,089,432	$ 462,072
Expenses:
Total expenses	211,542	90,605	515,081	205,811
Income from real estate-related securities and loans	52,568	28,647	166,035	59,279
Segment net operating income	279,059	138,204	740,386	315,540
Depreciation and amortization	(204,653)	(103,758)	(505,986)	(262,708)
General and administrative	(4,548)	(3,027)	(12,607)	(7,973)
Management fee	(29,858)	(11,823)	(69,522)	(28,073)
Performance participation allocation	(56,322)	(12,447)	(106,383)	(29,796)
Gain on disposition of real estate	6,481		36,167
Interest income	1,763	82	2,260	280
Interest expense	(116,037)	(65,711)	(310,903)	(146,943)
Other income (expense)	(2,379)	(283)	(2,786)	(672)
Net loss	(126,494)	(58,763)	(229,374)	(160,345)
Net loss attributable to non-controlling interests in third party joint ventures	1,305	433	4,311	3,054
Net loss attributable to non-controlling interests in BREIT OP	2,018	663	4,342	1,594
Net loss attributable to BREIT stockholders	(123,171)	(57,667)	(220,721)	(155,697)
Multifamily [Member]
Revenues:
Total revenues	195,068	100,185	498,858	240,612
Expenses:
Total expenses	90,149	46,196	225,745	112,775
Segment net operating income	104,919	53,989	273,113	127,837
Depreciation and amortization	(128,043)	(62,929)	(303,208)	(166,983)
Industrial [Member]
Revenues:
Total revenues	102,114	56,630	269,095	134,644
Expenses:
Total expenses	28,813	16,818	79,870	38,681
Segment net operating income	73,301	39,812	189,225	95,963
Depreciation and amortization	(52,720)	(31,966)	(145,145)	(77,786)
Hotel [Member]
Revenues:
Total revenues	134,178	40,781	308,597	79,798
Expenses:
Total expenses	89,951	26,822	204,468	51,958
Segment net operating income	44,227	13,959	104,129	27,840
Depreciation and amortization	(19,003)	(7,633)	(49,686)	(14,643)
Retail [Member]
Revenues:
Total revenues	3,814	2,566	10,023	7,018
Expenses:
Total expenses	1,387	769	3,756	2,397
Segment net operating income	2,427	1,797	6,267	4,621
Depreciation and amortization	(1,938)	(1,230)	(4,998)	(3,296)
Other Properties [Member]
Revenues:
Total revenues	2,859		2,859
Expenses:
Total expenses	1,242		1,242
Segment net operating income	1,617		1,617
Depreciation and amortization	(2,949)		(2,949)
Real Estate-Related Securities and Loans [Member]
Expenses:
Income from real estate-related securities and loans	52,568	28,647	166,035	59,279
Segment net operating income	52,568	28,647	166,035	59,279
Rental Property [Member]
Revenues:
Total revenues	290,453	152,838	750,322	366,213
Expenses:
Total expenses	121,591	63,783	310,613	153,853
Rental Property [Member] | Multifamily [Member]
Revenues:
Total revenues	183,429	93,848	470,570	224,975
Expenses:
Total expenses	90,149	46,196	225,745	112,775
Rental Property [Member] | Industrial [Member]
Revenues:
Total revenues	100,759	56,465	267,428	134,301
Expenses:
Total expenses	28,813	16,818	79,870	38,681
Rental Property [Member] | Retail [Member]
Revenues:
Total revenues	3,723	2,525	9,782	6,937
Expenses:
Total expenses	1,387	769	3,756	2,397
Rental Property [Member] | Other Properties [Member]
Revenues:
Total revenues	2,542		2,542
Expenses:
Total expenses	1,242		1,242
Hotel [Member]
Revenues:
Total revenues	132,036	40,000	301,653	79,017
Expenses:
Total expenses	89,951	26,822	204,468	51,958
Hotel [Member] | Hotel [Member]
Revenues:
Total revenues	132,036	40,000	301,653	79,017
Expenses:
Total expenses	89,951	26,822	204,468	51,958
Other Revenue [Member]
Revenues:
Total revenues	15,544	7,324	37,457	16,842
Other Revenue [Member] | Multifamily [Member]
Revenues:
Total revenues	11,639	6,337	28,288	15,637
Other Revenue [Member] | Industrial [Member]
Revenues:
Total revenues	1,355	165	1,667	343
Other Revenue [Member] | Hotel [Member]
Revenues:
Total revenues	2,142	781	6,944	781
Other Revenue [Member] | Retail [Member]
Revenues:
Total revenues	91	$ 41	241	$ 81
Other Revenue [Member] | Other Properties [Member]
Revenues:
Total revenues	$ 317		$ 317