Segment Reporting - Summary of Financial Results by Segment (Detail) - USD ($)		3 Months Ended		6 Months Ended
	Jan. 30, 2020	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenues:
Total revenues		$ 592,747,000	$ 354,308,000	$ 1,267,629,000	$ 651,399,000
Expenses:
Total expenses		231,558,000	164,408,000	499,252,000	303,539,000
Income from unconsolidated entities		25,336,000		38,605,000
Income (loss) from investments in real estate debt		492,889,000	51,784,000	(523,258,000)	113,467,000
Segment net operating income (loss)		879,414,000	241,684,000	283,724,000	461,327,000
Depreciation and amortization		(347,352,000)	(161,854,000)	(676,157,000)	(301,333,000)
General and administrative		(6,913,000)	(4,878,000)	(13,595,000)	(8,059,000)
Management fee		(53,423,000)	(22,487,000)	(102,925,000)	(39,664,000)
Performance participation allocation		0	(29,898,000)	0	(50,061,000)
Impairment of investments in real estate		(6,126,000)		(6,126,000)	0
Net gains on disposition of real estate	$ 400,000		29,686,000	371,000	29,686,000
Interest income		233,000	303,000	1,980,000	497,000
Interest expense		(176,579,000)	(103,279,000)	(365,083,000)	(194,866,000)
Loss on extinguishment of debt				(1,237,000)	0
Other income (expense)		29,078,000	(2,061,000)	(19,770,000)	(407,000)
Net income (loss)		318,332,000	(52,784,000)	(898,818,000)	(102,880,000)
Net loss attributable to non-controlling interests in third party joint ventures		966,000	970,000	1,203,000	3,006,000
Net income attributable to non-controlling interests in BREIT OP		(4,859,000)	1,110,000	11,967,000	2,324,000
Net income (loss) attributable to BREIT stockholders		314,439,000	(50,704,000)	(885,648,000)	(97,550,000)
Multifamily [Member]
Revenues:
Total revenues		255,800,000	168,281,000	495,004,000	303,790,000
Expenses:
Total expenses		115,236,000	73,772,000	219,796,000	135,596,000
Segment net operating income (loss)		140,564,000	94,509,000	275,208,000	168,194,000
Depreciation and amortization		(145,595,000)	(96,631,000)	(272,921,000)	(175,165,000)
Industrial [Member]
Revenues:
Total revenues		210,740,000	85,463,000	412,978,000	166,981,000
Expenses:
Total expenses		64,048,000	26,196,000	121,218,000	51,057,000
Segment net operating income (loss)		146,692,000	59,267,000	291,760,000	115,924,000
Depreciation and amortization		(138,798,000)	(47,403,000)	(276,922,000)	(92,425,000)
Net Lease [Member]
Revenues:
Total revenues		82,794,000		165,589,000
Expenses:
Total expenses		13,000		114,000
Income from unconsolidated entities		25,336,000		38,605,000
Segment net operating income (loss)		108,117,000		204,080,000
Depreciation and amortization		(29,040,000)		(57,195,000)
Hotel [Member]
Revenues:
Total revenues		23,044,000	97,426,000	152,090,000	174,419,000
Expenses:
Total expenses		44,523,000	63,197,000	143,829,000	114,517,000
Segment net operating income (loss)		(21,479,000)	34,229,000	8,261,000	59,902,000
Depreciation and amortization		(22,753,000)	(16,257,000)	(45,546,000)	(30,683,000)
Retail [Member]
Revenues:
Total revenues		12,907,000	3,138,000	27,428,000	6,209,000
Expenses:
Total expenses		4,331,000	1,243,000	7,751,000	2,369,000
Segment net operating income (loss)		8,576,000	1,895,000	19,677,000	3,840,000
Depreciation and amortization		(8,174,000)	(1,563,000)	(16,809,000)	(3,060,000)
Other Properties [Member]
Revenues:
Total revenues		4,361,000		8,372,000
Expenses:
Total expenses		2,341,000		4,443,000
Segment net operating income (loss)		2,020,000		3,929,000
Depreciation and amortization		(1,452,000)		(3,681,000)
Real Estate Debt [Member]
Expenses:
Income (loss) from investments in real estate debt		492,889,000	51,784,000	(523,258,000)	113,467,000
Segment net operating income (loss)		492,889,000	51,784,000	(523,258,000)	113,467,000
Office [Member]
Revenues:
Total revenues		3,101,000		6,168,000
Expenses:
Total expenses		1,066,000		2,101,000
Segment net operating income (loss)		2,035,000		4,067,000
Depreciation and amortization		(1,540,000)		(3,083,000)
Rental Property [Member]
Revenues:
Total revenues		553,717,000	247,672,000	1,085,812,000	459,869,000
Expenses:
Total expenses		187,035,000	101,211,000	355,423,000	189,022,000
Rental Property [Member] | Multifamily [Member]
Revenues:
Total revenues		241,793,000	159,243,000	468,912,000	287,141,000
Expenses:
Total expenses		115,236,000	73,772,000	219,796,000	135,596,000
Rental Property [Member] | Industrial [Member]
Revenues:
Total revenues		209,583,000	85,368,000	410,980,000	166,669,000
Expenses:
Total expenses		64,048,000	26,196,000	121,218,000	51,057,000
Rental Property [Member] | Net Lease [Member]
Revenues:
Total revenues		82,794,000		165,589,000
Expenses:
Total expenses		13,000		114,000
Rental Property [Member] | Retail [Member]
Revenues:
Total revenues		12,679,000	3,061,000	26,922,000	6,059,000
Expenses:
Total expenses		4,331,000	1,243,000	7,751,000	2,369,000
Rental Property [Member] | Other Properties [Member]
Revenues:
Total revenues		3,897,000		7,461,000
Expenses:
Total expenses		2,341,000		4,443,000
Rental Property [Member] | Office [Member]
Revenues:
Total revenues		2,971,000		5,948,000
Expenses:
Total expenses		1,066,000		2,101,000
Hotel [Member]
Revenues:
Total revenues		21,781,000	94,351,000	149,253,000	169,617,000
Expenses:
Total expenses		44,523,000	63,197,000	143,829,000	114,517,000
Hotel [Member] | Hotel [Member]
Revenues:
Total revenues		21,781,000	94,351,000	149,253,000	169,617,000
Expenses:
Total expenses		44,523,000	63,197,000	143,829,000	114,517,000
Other Revenue [Member]
Revenues:
Total revenues		17,249,000	12,285,000	32,564,000	21,913,000
Other Revenue [Member] | Multifamily [Member]
Revenues:
Total revenues		14,007,000	9,038,000	26,092,000	16,649,000
Other Revenue [Member] | Industrial [Member]
Revenues:
Total revenues		1,157,000	95,000	1,998,000	312,000
Other Revenue [Member] | Hotel [Member]
Revenues:
Total revenues		1,263,000	3,075,000	2,837,000	4,802,000
Other Revenue [Member] | Retail [Member]
Revenues:
Total revenues		228,000	$ 77,000	506,000	$ 150,000
Other Revenue [Member] | Other Properties [Member]
Revenues:
Total revenues		464,000		911,000
Other Revenue [Member] | Office [Member]
Revenues:
Total revenues		$ 130,000		$ 220,000