Fair Value of Financial Instruments - Additional Information (Detail) $ in Thousands			6 Months Ended		12 Months Ended
	Jun. 30, 2017 USD ($) Property		Jun. 30, 2017 USD ($) Property		Dec. 31, 2016 USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets Fair Value Disclosure	$ 85		$ 85		$ 206
Significant Unobservable Inputs (Level 3)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Volatility rate			49.00%		51.00%
Credit adjusted discount rate			9.50%		10.00%
Dividend rate			13.20%		10.00%
Significant Unobservable Inputs (Level 3) | Non-Recurring Fair Value Measurements | Broker’s Opinion
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Discount rate	11.60%
Assets Fair Value Disclosure	$ 40,300		$ 40,300
Number real estate asset | Property	2		2
Estimated fair value per linear foot of frontage	11
Terminal capitalization rate	7.25%
Significant Unobservable Inputs (Level 3) | Non-Recurring Fair Value Measurements | Discounted Cash Flow Valuation
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets Fair Value Disclosure	$ 44,200		$ 44,200
Number real estate asset | Property	3		3
Significant Unobservable Inputs (Level 3) | Non-Recurring Fair Value Measurements | Discounted Cash Flow Valuation | Retail Property Manager Reporting Unit
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Discount rate	18.00%
Assets Fair Value Disclosure	$ 1,975		$ 1,975
Significant Unobservable Inputs (Level 3) | Non-Recurring Fair Value Measurements | Discounted Cash Flow Valuation | Real Estate Property One
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Discount rate	10.50%
Terminal capitalization rate	7.40%
Significant Unobservable Inputs (Level 3) | Non-Recurring Fair Value Measurements | Discounted Cash Flow Valuation | Real Estate Property Two
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Discount rate	8.60%
Terminal capitalization rate	6.70%
Significant Unobservable Inputs (Level 3) | Non-Recurring Fair Value Measurements | Discounted Cash Flow Valuation | Real Estate Property Three
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Discount rate	8.80%
Terminal capitalization rate	7.70%
Significant Unobservable Inputs (Level 3) | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Discount rate			10.90%		11.50%
Significant Unobservable Inputs (Level 3) | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Discount rate			11.20%		11.80%
Significant Other Observable Inputs (Level 2)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets Fair Value Disclosure	$ 85	[1]	$ 85	[1]	$ 206	[2]
Significant Other Observable Inputs (Level 2) | Non-Recurring Fair Value Measurements | Purchase and Sale Agreement
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets Fair Value Disclosure	$ 65,900		$ 65,900
Number real estate asset | Property	3		3
Significant Other Observable Inputs (Level 2) | Non-Recurring Fair Value Measurements | Letter of Intent
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets Fair Value Disclosure	$ 27,500		$ 27,500
Number real estate asset | Property	1		1
Significant Other Observable Inputs (Level 2) | Non-Recurring Fair Value Measurements | Various Offers To Purchase Property
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets Fair Value Disclosure	$ 23,218		$ 23,218
Number real estate asset | Property	1		1

[1] During the six months ended June 30, 2017, there were no transfers between Level 1 and Level 2, and there were no transfers into and/or out of Level 3.

[2] During the year ended December 31, 2016, there were no transfers between Level 1 and Level 2, and there were no transfers into and/or out of Level 3.