Summarized Condensed Consolidating and Combining Information - Condensed Consolidating Balance Sheets (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Assets:
Real estate investments, net	$ 893,918	$ 645,614
Other real estate investments	13,872	8,477
Cash and cash equivalents	7,500	11,467	$ 25,320	$ 895
Accounts receivable	5,896	2,342
Prepaid expenses and other assets	1,369	2,083
Deferred financing costs, net	2,803	3,183
Investment in subsidiaries	0	0
Intercompany	0	0
Total assets	925,358	673,166
Liabilities and Equity:
Senior unsecured notes payable, net	255,294	254,229
Mortgage notes payable, net	0	94,676
Line of credit		45,000
Accounts payable and accrued liabilities	12,137	9,269
Dividends payable	11,075	7,704
Intercompany	0	0
Total liabilities	472,928	410,878
Equity:
Common stock, $0.01 par value; 500,000,000 shares authorized, 64,816,350 and 47,664,742 shares issued and outstanding as of December 31, 2016 and 2015, respectively	648	477
Additional paid-in capital	611,475	410,217
Cumulative distributions in excess of earnings	(159,693)	(148,406)
Total equity	452,430	262,288	113,462	162,689
Total liabilities and equity	925,358	673,166
Senior unsecured term loan, net [Member]
Liabilities and Equity:
Line of credit	99,422	0
Unsecured revolving credit facility [Member]
Liabilities and Equity:
Line of credit	95,000	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	0	0
Deferred financing costs, net	0	0
Investment in subsidiaries	463,505	269,992
Intercompany	0	0
Total assets	463,505	269,992
Liabilities and Equity:
Senior unsecured notes payable, net	0	0
Mortgage notes payable, net		0
Line of credit		0
Accounts payable and accrued liabilities	0	0
Dividends payable	11,075	7,704
Intercompany	0	0
Total liabilities	11,075	7,704
Equity:
Common stock, $0.01 par value; 500,000,000 shares authorized, 64,816,350 and 47,664,742 shares issued and outstanding as of December 31, 2016 and 2015, respectively	648	477
Additional paid-in capital	611,475	410,217
Cumulative distributions in excess of earnings	(159,693)	(148,406)
Total equity	452,430	262,288
Total liabilities and equity	463,505	269,992
Reportable Legal Entities [Member] | Parent Guarantor [Member] | Senior unsecured term loan, net [Member]
Liabilities and Equity:
Line of credit	0
Reportable Legal Entities [Member] | Parent Guarantor [Member] | Unsecured revolving credit facility [Member]
Liabilities and Equity:
Line of credit	0
Reportable Legal Entities [Member] | Issuers [Member]
Assets:
Real estate investments, net	527,639	256,209
Other real estate investments	0	0
Cash and cash equivalents	7,500	11,467	25,320	0
Accounts receivable	3,743	519
Prepaid expenses and other assets	1,366	2,079
Deferred financing costs, net	2,803	3,183
Investment in subsidiaries	401,328	365,368
Intercompany	0	0
Total assets	944,379	638,825
Liabilities and Equity:
Senior unsecured notes payable, net	255,294	254,229
Mortgage notes payable, net		0
Line of credit		45,000
Accounts payable and accrued liabilities	9,713	6,258
Dividends payable	0	0
Intercompany	21,445	63,346
Total liabilities	480,874	368,833
Equity:
Common stock, $0.01 par value; 500,000,000 shares authorized, 64,816,350 and 47,664,742 shares issued and outstanding as of December 31, 2016 and 2015, respectively	0	0
Additional paid-in capital	429,453	266,929
Cumulative distributions in excess of earnings	34,052	3,063
Total equity	463,505	269,992
Total liabilities and equity	944,379	638,825
Reportable Legal Entities [Member] | Issuers [Member] | Senior unsecured term loan, net [Member]
Liabilities and Equity:
Line of credit	99,422
Reportable Legal Entities [Member] | Issuers [Member] | Unsecured revolving credit facility [Member]
Liabilities and Equity:
Line of credit	95,000
Reportable Legal Entities [Member] | Combined Subsidiary Guarantors [Member]
Assets:
Real estate investments, net	328,137	348,454
Other real estate investments	13,872	8,477
Cash and cash equivalents	0	0	0	895
Accounts receivable	2,020	1,695
Prepaid expenses and other assets	3	4
Deferred financing costs, net	0	0
Investment in subsidiaries	0	0
Intercompany	102,273	59,160
Total assets	446,305	417,790
Liabilities and Equity:
Senior unsecured notes payable, net	0	0
Mortgage notes payable, net		0
Line of credit		0
Accounts payable and accrued liabilities	2,291	2,433
Dividends payable	0	0
Intercompany	0	0
Total liabilities	2,291	2,433
Equity:
Common stock, $0.01 par value; 500,000,000 shares authorized, 64,816,350 and 47,664,742 shares issued and outstanding as of December 31, 2016 and 2015, respectively	0	0
Additional paid-in capital	374,660	374,660
Cumulative distributions in excess of earnings	69,354	40,697
Total equity	444,014	415,357
Total liabilities and equity	446,305	417,790
Reportable Legal Entities [Member] | Combined Subsidiary Guarantors [Member] | Senior unsecured term loan, net [Member]
Liabilities and Equity:
Line of credit	0
Reportable Legal Entities [Member] | Combined Subsidiary Guarantors [Member] | Unsecured revolving credit facility [Member]
Liabilities and Equity:
Line of credit	0
Reportable Legal Entities [Member] | Combined Non-Guarantor Subsidiaries [Member]
Assets:
Real estate investments, net	38,142	40,951
Other real estate investments	0	0
Cash and cash equivalents	0	0	0	0
Accounts receivable	133	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	38,275	45,265
Liabilities and Equity:
Senior unsecured notes payable, net	0	0
Mortgage notes payable, net		94,676
Line of credit		0
Accounts payable and accrued liabilities	133	578
Dividends payable	0	0
Intercompany	80,828	0
Total liabilities	80,961	95,254
Equity:
Common stock, $0.01 par value; 500,000,000 shares authorized, 64,816,350 and 47,664,742 shares issued and outstanding as of December 31, 2016 and 2015, respectively	0	0
Additional paid-in capital	(52,899)	(52,899)
Cumulative distributions in excess of earnings	10,213	2,910
Total equity	(42,686)	(49,989)
Total liabilities and equity	38,275	45,265
Reportable Legal Entities [Member] | Combined Non-Guarantor Subsidiaries [Member] | Senior unsecured term loan, net [Member]
Liabilities and Equity:
Line of credit	0
Reportable Legal Entities [Member] | Combined Non-Guarantor Subsidiaries [Member] | Unsecured revolving credit facility [Member]
Liabilities and Equity:
Line of credit	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	(864,833)	(635,360)
Intercompany	(102,273)	(63,346)
Total assets	(967,106)	(698,706)
Liabilities and Equity:
Senior unsecured notes payable, net	0	0
Mortgage notes payable, net		0
Line of credit		0
Accounts payable and accrued liabilities	0	0
Dividends payable	0	0
Intercompany	(102,273)	(63,346)
Total liabilities	(102,273)	(63,346)
Equity:
Common stock, $0.01 par value; 500,000,000 shares authorized, 64,816,350 and 47,664,742 shares issued and outstanding as of December 31, 2016 and 2015, respectively	0	0
Additional paid-in capital	(751,214)	(588,690)
Cumulative distributions in excess of earnings	(113,619)	(46,670)
Total equity	(864,833)	(635,360)
Total liabilities and equity	(967,106)	$ (698,706)
Elimination [Member] | Senior unsecured term loan, net [Member]
Liabilities and Equity:
Line of credit	0
Elimination [Member] | Unsecured revolving credit facility [Member]
Liabilities and Equity:
Line of credit	$ 0