Principal Business and Organization - Additional Information (Detail) - Class T, Class S (Formerly Class T-C), Class D, Class M and Class I shares [Member] - Maximum [Member]	12 Months Ended
	Dec. 31, 2018 USD ($)
Subsidiary, Sale of Stock [Line Items]
Common stock value submitted for approval under initial public offering	$ 2,750,000,000
Primary Offering [Member]
Subsidiary, Sale of Stock [Line Items]
Common stock value submitted for approval under initial public offering	2,500,000,000
Distribution Reinvestment Plan [Member]
Subsidiary, Sale of Stock [Line Items]
Common stock value submitted for approval under initial public offering	$ 250,000,000