Debt, net - Additional Information (Detail) - USD ($)		3 Months Ended	6 Months Ended
	May 12, 2017	Jun. 30, 2017	Jun. 30, 2017	Jun. 30, 2016	May 11, 2017	Dec. 31, 2016
Line of Credit Facility [Line Items]
Deferred finance costs, net		$ 1,393,000	$ 1,393,000			$ 1,633,000
Amortization of deferred financing fees			$ 574,000	$ 1,877,000
Senior Notes
Line of Credit Facility [Line Items]
Interest rate percentage		8.50%	8.50%			8.50%
Senior Secured Credit Facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity under term loan facility	$ 50,000,000				$ 125,000,000
Line of credit facility, expiration date			May 15, 2018
Length of extensions	1 year
Amount drawn on		$ 0
Sublimit for letters of credit outstanding		15,719,000	$ 15,719,000
Net unused borrowing capacity		$ 14,240,000	$ 14,240,000
Percentage of spread on federal funds effective rate			0.50%
Effective leverage ratio (less than)		40.00%	40.00%
Stockholders distribution covenant, interest coverage ratio		3.0	3.0
Minimum liquidity required by covenant (less than)			$ 125,000,000
Payments of capital distribution			$ 50,000,000
Percentage from sales of properties and non-core assets (up to)		65.00%	65.00%
Deferred finance costs, net		$ 129,000	$ 129,000			$ 314,000
Senior Secured Credit Facility | LIBOR
Line of Credit Facility [Line Items]
Debt instrument, basis spread on variable rate			4.00%
Senior Secured Credit Facility | Base Rate
Line of Credit Facility [Line Items]
Percentage of variable spread on base rate			3.00%
Senior Secured Credit Facility | 30 day LIBOR rate
Line of Credit Facility [Line Items]
Debt instrument, basis spread on variable rate			1.00%
Senior Secured Credit Facility | Letter of Credit
Line of Credit Facility [Line Items]
Line of credit facility, letters of credit sublimit		$ 50,000,000	$ 50,000,000