Equity and Redeemable Non-controlling Interest - Schedule of Aggregate Distributions Declared for Applicable Class of Common Stock (Detail) - $ / shares	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Dividends Payable [Line Items]
Aggregate gross distributions declared per share of common stock	$ 0.1582	$ 0.1552
Class S Shares [Member]
Dividends Payable [Line Items]
Aggregate gross distributions declared per share of common stock	0.1582
Stockholder servicing fee per share of common stock	(0.0229)
Net distributions declared per share of common stock	0.1353
Class T Shares [Member]
Dividends Payable [Line Items]
Aggregate gross distributions declared per share of common stock	0.1582
Stockholder servicing fee per share of common stock	(0.0226)
Net distributions declared per share of common stock	0.1356
Class D Shares [Member]
Dividends Payable [Line Items]
Aggregate gross distributions declared per share of common stock	0.1582
Stockholder servicing fee per share of common stock	(0.0067)
Net distributions declared per share of common stock	0.1515
Class I Shares [Member]
Dividends Payable [Line Items]
Aggregate gross distributions declared per share of common stock	0.1582
Net distributions declared per share of common stock	$ 0.1582