Subsequent Events - Additional Information (Detail) $ in Thousands			9 Months Ended
	Nov. 13, 2018 USD ($) shares	Oct. 01, 2018 USD ($) Transaction	Sep. 30, 2018 USD ($) shares	Sep. 30, 2017 USD ($)	Dec. 31, 2017 shares
Subsequent Event [Line Items]
Aggregate payments to acquire real estate, exclusive of closing costs | $			$ 5,693,880	$ 2,245,885
Acquisition of real estate-related securities | $			1,227,708	660,151
Proceeds from issuance of common stock | $			$ 1,948,928	$ 1,264,053
Class S Shares [Member]
Subsequent Event [Line Items]
Common stock, shares issued			237,262,632		130,085,145
Class I Shares [Member]
Subsequent Event [Line Items]
Common stock, shares issued			87,082,488		30,719,160
Class D Shares [Member]
Subsequent Event [Line Items]
Common stock, shares issued			24,178,629		3,955,114
Class T Shares [Member]
Subsequent Event [Line Items]
Common stock, shares issued			19,227,318		5,624,614
Subsequent Event [Member]
Subsequent Event [Line Items]
Aggregate payments to acquire real estate, exclusive of closing costs | $		$ 993,100
Number of separate transaction in real estate acquisition | Transaction		3
Common stock, shares issued	415,835,450
Proceeds from issuance of common stock | $	$ 4,300,000
Subsequent Event [Member] | Class S Shares [Member]
Subsequent Event [Line Items]
Common stock, shares issued	266,113,175
Subsequent Event [Member] | Class I Shares [Member]
Subsequent Event [Line Items]
Common stock, shares issued	99,359,504
Subsequent Event [Member] | Class D Shares [Member]
Subsequent Event [Line Items]
Common stock, shares issued	28,572,626
Subsequent Event [Member] | Class T Shares [Member]
Subsequent Event [Line Items]
Common stock, shares issued	21,790,145
Subsequent Event [Member] | Real Estate-Related Securities [Member]
Subsequent Event [Line Items]
Acquisition of real estate-related securities | $		$ 222,700