Related Party Transactions - Related Party Description (Detail) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Related Party Transaction [Line Items]
Issuance of common stock	$ (14,000)	$ 88,715,000
Board of Directors Chairman [Member]
Related Party Transaction [Line Items]
Issuance of common stock		$ 10,000
Issuance of common stock, shares		995
President [Member]
Related Party Transaction [Line Items]
Issuance of common stock		$ 11,000
Issuance of common stock, shares		1,103
Executive Vice President [Member]
Related Party Transaction [Line Items]
Issuance of common stock		$ 10,000
Issuance of common stock, shares		999
Chief Financial Officer [Member]
Related Party Transaction [Line Items]
Issuance of common stock		$ 1,000
Issuance of common stock, shares		88
Executive Vice President, Acquisitions [Member]
Related Party Transaction [Line Items]
Issuance of common stock		$ 1,000
Issuance of common stock, shares		127
Executive Officer [Member]
Related Party Transaction [Line Items]
Issuance of common stock		$ 35,000
Issuance of common stock, shares		3,448
Christopher M. Belford [Member] | Executive Vice President, Asset Management [Member]
Related Party Transaction [Line Items]
Issuance of common stock		$ 1,000
Issuance of common stock, shares		102
Wendie Newman [Member] | Executive Vice President, Asset Management [Member]
Related Party Transaction [Line Items]
Issuance of common stock		$ 1,000
Issuance of common stock, shares		34