Summary of Significant Accounting Policies (Detail)		3 Months Ended		6 Months Ended
	Jul. 01, 2016 USD ($) a	Jun. 30, 2017 USD ($) ft²	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($) ft²	Jun. 30, 2016 USD ($)	Jun. 23, 2017 USD ($)	Dec. 31, 2016 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Rentable square feet | ft²		1,764,112		1,764,112
Allocation period		1 year
Interest capitalized		$ 500,000	$ 400,000	$ 924,000	$ 882,000
Real estate taxes and insurance costs capitalized		$ 300,000	200,000	600,000	400,000
REIT annual taxable income distribution requirement percentage		90.00%
Income tax provision		$ 0	0	0	0
Rents and other receivables		4,910,000		4,910,000			$ 5,565,000
Allowance for doubtful accounts		(2,266,000)		(2,266,000)			(2,816,000)
Rents and other receivables, net		2,644,000		2,644,000			2,749,000
Deferred rent receivable		13,694,000		13,694,000			11,903,000
Allowance for doubtful accounts		(66,000)		(66,000)			(30,000)
Deferred rent receivable, net		13,628,000		13,628,000			$ 11,873,000
Provision for doubtful accounts		340,000	368,000	666,000	833,000
Net cash used in investing activities				(189,163,000)	(223,401,000)
Restricted cash			18,000,000		18,000,000
Previously Reported
Summary Of Significant Accounting Policies [Line Items]
Net cash used in investing activities					241,400,000
Construction Employees
Summary Of Significant Accounting Policies [Line Items]
Compensation costs capitalized		500,000	300,000	800,000	500,000
Leasing Employees
Summary Of Significant Accounting Policies [Line Items]
Compensation costs capitalized		$ 200,000	$ 100,000	$ 400,000	$ 200,000
Minimum
Summary Of Significant Accounting Policies [Line Items]
Fair value inputs, discount rate		6.25%
Fair value inputs, capitalization rate		5.25%
Estimated average lease-up period				6 months
Minimum | Building
Summary Of Significant Accounting Policies [Line Items]
Estimated remaining life		10 years
Minimum | Site Improvements
Summary Of Significant Accounting Policies [Line Items]
Estimated remaining life		5 years
Maximum
Summary Of Significant Accounting Policies [Line Items]
Fair value inputs, discount rate		9.50%
Fair value inputs, capitalization rate		7.50%
Estimated average lease-up period					18 months
Maximum | Building
Summary Of Significant Accounting Policies [Line Items]
Estimated remaining life		30 years
Maximum | Site Improvements
Summary Of Significant Accounting Policies [Line Items]
Estimated remaining life		20 years
Rancho Cucamonga, CA
Summary Of Significant Accounting Policies [Line Items]
Mortgage loan, face amount	$ 6,000,000
Rentable square feet | a	64,965
Proceeds from fees received	$ 300,000
Interest rate	10.00%
Deferred interest	$ 14,000
Mortgage loans, carrying amount						$ 6,200,000