Summarized Condensed Consolidating and Combining Information - Condensed Consolidating Balance Sheets (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014	Dec. 31, 2013
Assets:
Real estate investments, net	$ 459,515	$ 436,215
Other real estate investments	7,987	7,532
Cash and cash equivalents	29,904	25,320	$ 80,345	$ 895
Accounts receivable	2,036	2,291
Prepaid expenses and other assets	2,292	809
Deferred financing costs, net	9,442	10,405
Investment in subsidiaries	0	0
Intercompany	0	0
Total assets	511,176	482,572
Liabilities and Equity:
Senior unsecured notes payable	260,000	260,000
Mortgage notes payable	96,854	98,205
Secured revolving credit facility	35,000	0
Accounts payable and accrued liabilities	5,946	6,959
Dividends payable	5,090	3,946
Intercompany	0	0
Total liabilities	402,890	369,110
Equity:
Common stock, $0.01 par value; 500,000,000 shares authorized, 31,306,782 and 31,251,157 shares issued and outstanding as of June 30, 2015 and December 31, 2014, respectively	313	313
Additional paid-in capital	246,701	246,041
Cumulative distributions in excess of earnings	(138,728)	(132,892)
Total equity	108,286	113,462		162,689
Total liabilities and equity	511,176	482,572
Reportable Legal Entities [Member] | Parent Guarantor [Member]
Assets:
Real estate investments, net	0	0
Other real estate investments	0	0
Cash and cash equivalents	0	0	0	0
Accounts receivable	0	0
Prepaid expenses and other assets	133	0
Deferred financing costs, net	0	0
Investment in subsidiaries	113,243	117,408
Intercompany	0	0
Total assets	113,376	117,408
Liabilities and Equity:
Senior unsecured notes payable	0	0
Mortgage notes payable	0	0
Secured revolving credit facility	0
Accounts payable and accrued liabilities	0	0
Dividends payable	5,090	3,946
Intercompany	0	0
Total liabilities	5,090	3,946
Equity:
Common stock, $0.01 par value; 500,000,000 shares authorized, 31,306,782 and 31,251,157 shares issued and outstanding as of June 30, 2015 and December 31, 2014, respectively	313	313
Additional paid-in capital	246,701	246,041
Cumulative distributions in excess of earnings	(138,728)	(132,892)
Total equity	108,286	113,462
Total liabilities and equity	113,376	117,408
Reportable Legal Entities [Member] | Issuers [Member]
Assets:
Real estate investments, net	59,790	26,104
Other real estate investments	0	0
Cash and cash equivalents	29,904	25,320	80,345	0
Accounts receivable	122	0
Prepaid expenses and other assets	2,155	808
Deferred financing costs, net	8,970	9,808
Investment in subsidiaries	350,032	335,020
Intercompany	0	0
Total assets	450,973	397,060
Liabilities and Equity:
Senior unsecured notes payable	260,000	260,000
Mortgage notes payable	0	0
Secured revolving credit facility	35,000
Accounts payable and accrued liabilities	3,161	3,067
Dividends payable	0	0
Intercompany	39,569	16,585
Total liabilities	337,730	279,652
Equity:
Common stock, $0.01 par value; 500,000,000 shares authorized, 31,306,782 and 31,251,157 shares issued and outstanding as of June 30, 2015 and December 31, 2014, respectively	0	0
Additional paid-in capital	116,773	125,551
Cumulative distributions in excess of earnings	(3,530)	(8,143)
Total equity	113,243	117,408
Total liabilities and equity	450,973	397,060
Reportable Legal Entities [Member] | Combined Subsidiary Guarantors [Member]
Assets:
Real estate investments, net	357,318	366,199
Other real estate investments	7,987	7,532
Cash and cash equivalents	0	0	0	895
Accounts receivable	1,790	2,170
Prepaid expenses and other assets	4	1
Deferred financing costs, net	0	0
Investment in subsidiaries	0	0
Intercompany	36,831	15,262
Total assets	403,930	391,164
Liabilities and Equity:
Senior unsecured notes payable	0	0
Mortgage notes payable	507	557
Secured revolving credit facility	0
Accounts payable and accrued liabilities	2,219	3,308
Dividends payable	0	0
Intercompany	0	0
Total liabilities	2,726	3,865
Equity:
Common stock, $0.01 par value; 500,000,000 shares authorized, 31,306,782 and 31,251,157 shares issued and outstanding as of June 30, 2015 and December 31, 2014, respectively	0	0
Additional paid-in capital	374,660	374,660
Cumulative distributions in excess of earnings	26,544	12,639
Total equity	401,204	387,299
Total liabilities and equity	403,930	391,164
Reportable Legal Entities [Member] | Combined Non-Guarantor Subsidiaries [Member]
Assets:
Real estate investments, net	42,407	43,912
Other real estate investments	0	0
Cash and cash equivalents	0	0	0	0
Accounts receivable	124	121
Prepaid expenses and other assets	0	0
Deferred financing costs, net	472	597
Investment in subsidiaries	0	0
Intercompany	2,738	1,323
Total assets	45,741	45,953
Liabilities and Equity:
Senior unsecured notes payable	0	0
Mortgage notes payable	96,347	97,648
Secured revolving credit facility	0
Accounts payable and accrued liabilities	566	584
Dividends payable	0	0
Intercompany	0	0
Total liabilities	96,913	98,232
Equity:
Common stock, $0.01 par value; 500,000,000 shares authorized, 31,306,782 and 31,251,157 shares issued and outstanding as of June 30, 2015 and December 31, 2014, respectively	0	0
Additional paid-in capital	(52,899)	(52,899)
Cumulative distributions in excess of earnings	1,727	620
Total equity	(51,172)	(52,279)
Total liabilities and equity	45,741	45,953
Elimination [Member]
Assets:
Real estate investments, net	0	0
Other real estate investments	0	0
Cash and cash equivalents	0	0	$ 0	$ 0
Accounts receivable	0	0
Prepaid expenses and other assets	0	0
Deferred financing costs, net	0	0
Investment in subsidiaries	(463,275)	(452,428)
Intercompany	(39,569)	(16,585)
Total assets	(502,844)	(469,013)
Liabilities and Equity:
Senior unsecured notes payable	0	0
Mortgage notes payable	0	0
Secured revolving credit facility	0
Accounts payable and accrued liabilities	0	0
Dividends payable	0	0
Intercompany	(39,569)	(16,585)
Total liabilities	(39,569)	(16,585)
Equity:
Common stock, $0.01 par value; 500,000,000 shares authorized, 31,306,782 and 31,251,157 shares issued and outstanding as of June 30, 2015 and December 31, 2014, respectively	0	0
Additional paid-in capital	(438,534)	(447,312)
Cumulative distributions in excess of earnings	(24,741)	(5,116)
Total equity	(463,275)	(452,428)
Total liabilities and equity	$ (502,844)	$ (469,013)