Subsequent Events - Additional Information (Detail)				7 Months Ended	9 Months Ended
	Nov. 13, 2017 USD ($) shares	Oct. 27, 2017 USD ($)	Oct. 01, 2017 USD ($) Transaction	Sep. 30, 2016 USD ($)	Sep. 30, 2017 USD ($) shares	Dec. 31, 2016 shares
Subsequent Event [Line Items]
Aggregate payments to acquire real estate, exclusive of closing costs | $				$ 0	$ 2,245,885,000
Purchase of floating-rate CMBS | $				0	$ 660,151,000
Common stock, shares issued					125,491,201
Proceeds from issuance of common stock | $				$ 0	$ 1,264,053,000
Class S Shares [Member]
Subsequent Event [Line Items]
Common stock, shares issued					98,779,308	0
Class I Shares [Member]
Subsequent Event [Line Items]
Common stock, shares issued					23,277,430	20,000
Class D Shares [Member]
Subsequent Event [Line Items]
Common stock, shares issued					1,225,700	0
Class T Shares [Member]
Subsequent Event [Line Items]
Common stock, shares issued					2,208,763	0
Subsequent Event [Member]
Subsequent Event [Line Items]
Aggregate payments to acquire real estate, exclusive of closing costs | $			$ 383,800,000
Number of separate transaction in real estate acquisition | Transaction			4
Common stock, shares issued	152,942,761
Proceeds from issuance of common stock | $	$ 1,500,000,000
Subsequent Event [Member] | Class S Shares [Member]
Subsequent Event [Line Items]
Common stock, shares issued	117,771,673
Subsequent Event [Member] | Class I Shares [Member]
Subsequent Event [Line Items]
Common stock, shares issued	27,873,679
Subsequent Event [Member] | Class D Shares [Member]
Subsequent Event [Line Items]
Common stock, shares issued	2,981,473
Subsequent Event [Member] | Class T Shares [Member]
Subsequent Event [Line Items]
Common stock, shares issued	4,315,936
Subsequent Event [Member] | Revolving Credit Facility [Member] | Citi Bank, N.A. [Member]
Subsequent Event [Line Items]
Revolving credit facility, face amount | $		$ 300,000,000
Debt instrument, Initial maturity date		Oct. 26, 2018
Debt instrument, Extension term		Two one year
Funds drawn under revolving credit facility | $	$ 0
Subsequent Event [Member] | Revolving Credit Facility [Member] | Citi Bank, N.A. [Member] | London Interbank Offered Rate (LIBOR) [Member]
Subsequent Event [Line Items]
Interest rate		2.25%
Subsequent Event [Member] | Commercial Mortgage Backed Securities [Member]
Subsequent Event [Line Items]
Purchase of floating-rate CMBS | $	$ 150,800,000