Segment Reporting - Summary of Financial Results by Segment (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenues:
Total revenues	$ 297,091	$ 109,684
Expenses:
Total expenses	139,131	50,232
Income from real estate-related securities and loans	61,683	13,235
Segment net operating income	219,643	72,687
Depreciation and amortization	139,479	74,124
Other income (expense):
General and administrative	(3,181)	(2,045)
Management fee	(17,177)	(6,969)
Performance participation allocation	(20,163)	(7,873)
Interest income	194	77
Interest expense	(91,587)	(31,391)
Other income (expense)	1,654
Net loss	(50,096)	(49,638)
Net loss attributable to non-controlling interests in third party joint ventures	2,036	1,716
Net loss attributable to non-controlling interests in BREIT OP	1,214	374
Net loss attributable to BREIT stockholders	(46,846)	(47,548)
Multifamily [Member]
Revenues:
Total revenues	135,509	64,980
Expenses:
Total expenses	61,824	30,620
Segment net operating income	73,685	34,360
Depreciation and amortization	78,534	55,873
Industrial [Member]
Revenues:
Total revenues	81,518	24,639
Expenses:
Total expenses	24,861	7,185
Segment net operating income	56,657	17,454
Depreciation and amortization	45,022	13,998
Hotel [Member]
Revenues:
Total revenues	76,993	17,829
Expenses:
Total expenses	51,320	11,614
Segment net operating income	25,673	6,215
Depreciation and amortization	14,426	3,210
Retail [Member]
Revenues:
Total revenues	3,071	2,236
Expenses:
Total expenses	1,126	813
Segment net operating income	1,945	1,423
Depreciation and amortization	1,497	1,043
Real Estate-Related Securities and Loans [Member]
Expenses:
Income from real estate-related securities and loans	61,683	13,235
Segment net operating income	61,683	13,235
Rental Property [Member]
Revenues:
Total revenues	212,197	87,561
Expenses:
Total expenses	87,811	38,618
Rental Property [Member] | Multifamily [Member]
Revenues:
Total revenues	127,898	60,743
Expenses:
Total expenses	61,824	30,620
Rental Property [Member] | Industrial [Member]
Revenues:
Total revenues	81,301	24,601
Expenses:
Total expenses	24,861	7,185
Rental Property [Member] | Retail [Member]
Revenues:
Total revenues	2,998	2,217
Expenses:
Total expenses	1,126	813
Hotel [Member]
Revenues:
Total revenues	75,266	17,821
Expenses:
Total expenses	51,320	11,614
Hotel [Member] | Hotel [Member]
Revenues:
Total revenues	75,266	17,821
Expenses:
Total expenses	51,320	11,614
Other Revenue [Member]
Revenues:
Total revenues	9,628	4,302
Other Revenue [Member] | Multifamily [Member]
Revenues:
Total revenues	7,611	4,237
Other Revenue [Member] | Industrial [Member]
Revenues:
Total revenues	217	38
Other Revenue [Member] | Hotel [Member]
Revenues:
Total revenues	1,727	8
Other Revenue [Member] | Retail [Member]
Revenues:
Total revenues	$ 73	$ 19