Summary of Significant Accounting Policies - Additional Information (Detail) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2017 USD ($)	Sep. 30, 2017 USD ($)
Significant Of Accounting Policies [Line Items]
Subscriptions received in advance	$ 98,435	$ 98,435
Investments in real estate-related securities	$ 644,371	$ 644,371
Percentage of taxable income distributed to stockholders	90.00%	90.00%
Tax benefit	$ 184	$ 140
Class S Shares [Member]
Significant Of Accounting Policies [Line Items]
Percentage of stockholder servicing fee on NAV per annum		0.85%
Class T Shares [Member]
Significant Of Accounting Policies [Line Items]
Percentage of stockholder servicing fee on NAV per annum		0.85%
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	76,000	$ 76,000
Adviser [Member]
Significant Of Accounting Policies [Line Items]
Period for reimbursement of advance expenses		60 months
Organizational and offering costs	9,400	$ 9,400
Offering cost	7,600	7,600
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 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 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 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%
UC Davis Hotel [Member]
Significant Of Accounting Policies [Line Items]
Tax benefit		$ 246
Level 2 [Member]
Significant Of Accounting Policies [Line Items]
Investments in real estate-related securities	$ 644,400	$ 644,400