Summarized Condensed Consolidating Information - Condensed Consolidating Balance Sheets (Detail) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2015	Dec. 31, 2014
Assets:
Real estate investments, net	$ 776,227	$ 645,614
Other real estate investments	8,992	8,477
Cash and cash equivalents	9,644	11,467	$ 29,904	$ 25,320
Accounts receivable	4,085	2,342
Prepaid expenses and other assets	1,197	2,083
Deferred financing costs, net	3,333	3,183
Investment in subsidiaries	0	0
Intercompany	0	0
Total assets	803,478	673,166
Liabilities and Equity:
Senior unsecured notes payable, net	254,762	254,229
Mortgage notes payable, net	0	94,676
Accounts payable and accrued liabilities	9,633	9,269
Dividends payable	9,847	7,704
Intercompany	0	0
Total liabilities	441,624	410,878
Equity:
Common stock, $0.01 par value; 500,000,000 shares authorized, 57,548,876 and 47,664,742 shares issued and outstanding as of June 30, 2016 and December 31, 2015, respectively	575	477
Additional paid-in capital	516,243	410,217
Cumulative distributions in excess of earnings	(154,964)	(148,406)
Total equity	361,854	262,288		113,462
Total liabilities and equity	803,478	673,166
Senior Unsecured Term Loan [Member]
Liabilities and Equity:
Revolving credit facility	99,382	0
Unsecured Revolving Credit Facility [Member]
Liabilities and Equity:
Revolving credit facility	68,000	45,000
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	147	0
Deferred financing costs, net	0	0
Investment in subsidiaries	372,287	269,992
Intercompany	0	0
Total assets	372,434	269,992
Liabilities and Equity:
Senior unsecured notes payable, net	0	0
Mortgage notes payable, net		0
Accounts payable and accrued liabilities	733	0
Dividends payable	9,847	7,704
Intercompany	0	0
Total liabilities	10,580	7,704
Equity:
Common stock, $0.01 par value; 500,000,000 shares authorized, 57,548,876 and 47,664,742 shares issued and outstanding as of June 30, 2016 and December 31, 2015, respectively	575	477
Additional paid-in capital	516,243	410,217
Cumulative distributions in excess of earnings	(154,964)	(148,406)
Total equity	361,854	262,288
Total liabilities and equity	372,434	269,992
Reportable Legal Entities [Member] | Parent Guarantor [Member] | Senior Unsecured Term Loan [Member]
Liabilities and Equity:
Revolving credit facility	0
Reportable Legal Entities [Member] | Parent Guarantor [Member] | Unsecured Revolving Credit Facility [Member]
Liabilities and Equity:
Revolving credit facility	0	0
Reportable Legal Entities [Member] | Issuers [Member]
Assets:
Real estate investments, net	396,908	256,209
Other real estate investments	0	0
Cash and cash equivalents	9,644	11,467	29,904	25,320
Accounts receivable	2,219	519
Prepaid expenses and other assets	1,044	2,079
Deferred financing costs, net	3,333	3,183
Investment in subsidiaries	382,968	365,368
Intercompany	4,597	0
Total assets	800,713	638,825
Liabilities and Equity:
Senior unsecured notes payable, net	254,762	254,229
Mortgage notes payable, net		0
Accounts payable and accrued liabilities	6,282	6,258
Dividends payable	0	0
Intercompany	0	63,346
Total liabilities	428,426	368,833
Equity:
Common stock, $0.01 par value; 500,000,000 shares authorized, 57,548,876 and 47,664,742 shares issued and outstanding as of June 30, 2016 and December 31, 2015, respectively	0	0
Additional paid-in capital	355,221	266,929
Cumulative distributions in excess of earnings	17,066	3,063
Total equity	372,287	269,992
Total liabilities and equity	800,713	638,825
Reportable Legal Entities [Member] | Issuers [Member] | Senior Unsecured Term Loan [Member]
Liabilities and Equity:
Revolving credit facility	99,382
Reportable Legal Entities [Member] | Issuers [Member] | Unsecured Revolving Credit Facility [Member]
Liabilities and Equity:
Revolving credit facility	68,000	45,000
Reportable Legal Entities [Member] | Combined Subsidiary Guarantors [Member]
Assets:
Real estate investments, net	339,787	348,454
Other real estate investments	8,992	8,477
Cash and cash equivalents	0	0	0	0
Accounts receivable	1,710	1,695
Prepaid expenses and other assets	6	4
Deferred financing costs, net	0	0
Investment in subsidiaries	0	0
Intercompany	81,724	59,160
Total assets	432,219	417,790
Liabilities and Equity:
Senior unsecured notes payable, net	0	0
Mortgage notes payable, net		0
Accounts payable and accrued liabilities	2,462	2,433
Dividends payable	0	0
Intercompany	0	0
Total liabilities	2,462	2,433
Equity:
Common stock, $0.01 par value; 500,000,000 shares authorized, 57,548,876 and 47,664,742 shares issued and outstanding as of June 30, 2016 and December 31, 2015, respectively	0	0
Additional paid-in capital	374,660	374,660
Cumulative distributions in excess of earnings	55,097	40,697
Total equity	429,757	415,357
Total liabilities and equity	432,219	417,790
Reportable Legal Entities [Member] | Combined Subsidiary Guarantors [Member] | Senior Unsecured Term Loan [Member]
Liabilities and Equity:
Revolving credit facility	0
Reportable Legal Entities [Member] | Combined Subsidiary Guarantors [Member] | Unsecured Revolving Credit Facility [Member]
Liabilities and Equity:
Revolving credit facility	0	0
Reportable Legal Entities [Member] | Combined Non-Guarantor Subsidiaries [Member]
Assets:
Real estate investments, net	39,532	40,951
Other real estate investments	0	0
Cash and cash equivalents	0	0	0	0
Accounts receivable	156	128
Prepaid expenses and other assets	0	0
Deferred financing costs, net	0	0
Investment in subsidiaries	0	0
Intercompany	0	4,186
Total assets	39,688	45,265
Liabilities and Equity:
Senior unsecured notes payable, net	0	0
Mortgage notes payable, net		94,676
Accounts payable and accrued liabilities	156	578
Dividends payable	0	0
Intercompany	86,321	0
Total liabilities	86,477	95,254
Equity:
Common stock, $0.01 par value; 500,000,000 shares authorized, 57,548,876 and 47,664,742 shares issued and outstanding as of June 30, 2016 and December 31, 2015, respectively	0	0
Additional paid-in capital	(52,899)	(52,899)
Cumulative distributions in excess of earnings	6,110	2,910
Total equity	(46,789)	(49,989)
Total liabilities and equity	39,688	45,265
Reportable Legal Entities [Member] | Combined Non-Guarantor Subsidiaries [Member] | Senior Unsecured Term Loan [Member]
Liabilities and Equity:
Revolving credit facility	0
Reportable Legal Entities [Member] | Combined Non-Guarantor Subsidiaries [Member] | Unsecured Revolving Credit Facility [Member]
Liabilities and Equity:
Revolving credit facility	0	0
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	(755,255)	(635,360)
Intercompany	(86,321)	(63,346)
Total assets	(841,576)	(698,706)
Liabilities and Equity:
Senior unsecured notes payable, net	0	0
Mortgage notes payable, net		0
Accounts payable and accrued liabilities	0	0
Dividends payable	0	0
Intercompany	(86,321)	(63,346)
Total liabilities	(86,321)	(63,346)
Equity:
Common stock, $0.01 par value; 500,000,000 shares authorized, 57,548,876 and 47,664,742 shares issued and outstanding as of June 30, 2016 and December 31, 2015, respectively	0	0
Additional paid-in capital	(676,982)	(588,690)
Cumulative distributions in excess of earnings	(78,273)	(46,670)
Total equity	(755,255)	(635,360)
Total liabilities and equity	(841,576)	(698,706)
Elimination [Member] | Senior Unsecured Term Loan [Member]
Liabilities and Equity:
Revolving credit facility	0
Elimination [Member] | Unsecured Revolving Credit Facility [Member]
Liabilities and Equity:
Revolving credit facility	$ 0	$ 0