Summary of Significant Accounting Policies - Additional Information (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($)
Significant Of Accounting Policies [Line Items]
Assets excluding BREIT OP	$ 947,900
Liabilities excluding BREIT OP	645,500
Subscriptions received in advance	$ 107,576
Percentage of taxable income distributed to stockholders	90.00%
Investments in real estate-related securities	$ 915,742
Level 2 [Member]
Significant Of Accounting Policies [Line Items]
Investments in real estate-related securities	915,700
Hyatt Place Uc Davis
Significant Of Accounting Policies [Line Items]
Tax benefit	$ 300
Class T Shares [Member]
Significant Of Accounting Policies [Line Items]
Percentage of stockholder servicing fee on NAV per annum	0.85%
Selling commissions and dealer manager fees (% of transaction price)	3.50%
Upfront selling commissions and dealer manager fees (% of transaction price)	3.00%
Selling commissions and upfront dealer manager fees (% of transaction price)	0.50%
Advisor stockholder servicing fee (% of NAV)	0.65%
Dealer stockholder servicing fee (% of NAV)	0.20%
Class S Shares [Member]
Significant Of Accounting Policies [Line Items]
Percentage of stockholder servicing fee on NAV per annum	0.85%
Selling commissions and dealer manager fees (% of transaction price)	3.50%
Class D Shares [Member]
Significant Of Accounting Policies [Line Items]
Percentage of stockholder servicing fee on NAV per annum	0.25%
Class S Shares, Class D Shares and Class T Shares [Member]
Significant Of Accounting Policies [Line Items]
Stockholder servicing fees accrued	$ 102,100
Adviser [Member]
Significant Of Accounting Policies [Line Items]
Period for reimbursement of advance expenses	60 months
Organizational and offering costs	$ 10,200
Offering cost	8,400
Organization costs	$ 1,800
Blackstone Advisory Partners L.P. [Member]
Significant Of Accounting Policies [Line Items]
Commission and fees, threshold percentage on gross proceeds from sale of share	8.75%
Blackstone Advisory Partners L.P. [Member] | Class T Shares [Member]
Significant Of Accounting Policies [Line Items]
Percentage of stockholder servicing fee on NAV per annum	0.85%
Blackstone Advisory Partners L.P. [Member] | Class S Shares [Member]
Significant Of Accounting Policies [Line Items]
Percentage of stockholder servicing fee on NAV per annum	0.85%
Blackstone Advisory Partners L.P. [Member] | Class D Shares [Member]
Significant Of Accounting Policies [Line Items]
Percentage of stockholder servicing fee on NAV per annum	0.25%
Blackstone Advisory Partners L.P. [Member] | Class I Shares [Member]
Significant Of Accounting Policies [Line Items]
Percentage of stockholder servicing fee on NAV per annum	0.00%
In-place Lease Intangibles [Member]
Significant Of Accounting Policies [Line Items]
Intangible assets write off	$ 29,500