Equity and Redeemable Non-controlling Interest - Schedule of Company's Outstanding Shares of Common Stock (Detail)	9 Months Ended
	Sep. 30, 2019 shares
Class of Stock [Line Items]
Beginning balance	438,938,000
Common stock issued	466,147,000
Distribution reinvestment	14,665,000
Common stock repurchased	(14,655,000)
Independent directors' restricted stock grant	36,000
Ending balance	905,131,000
Class S Shares [Member]
Class of Stock [Line Items]
Beginning balance	276,989,019
Common stock issued	166,178,000
Distribution reinvestment	8,392,000
Common stock repurchased	(5,134,000)
Ending balance	446,424,565
Class T Shares [Member]
Class of Stock [Line Items]
Beginning balance	23,313,429
Common stock issued	13,440,000
Distribution reinvestment	630,000
Common stock repurchased	(824,000)
Ending balance	36,559,269
Class D Shares [Member]
Class of Stock [Line Items]
Beginning balance	30,375,353
Common stock issued	38,067,000
Distribution reinvestment	1,036,000
Common stock repurchased	(330,000)
Ending balance	69,148,152
Class I Shares [Member]
Class of Stock [Line Items]
Beginning balance	108,261,331
Common stock issued	248,462,000
Distribution reinvestment	4,607,000
Common stock repurchased	(8,367,000)
Independent directors' restricted stock grant	36,000
Ending balance	352,999,381