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Mortgage Notes Payable, Revolving Credit Facility, and Term Loan Facility - Additional Information (Detail) |  | 1 Months Ended | 12 Months Ended |
--- | --- | --- | --- | ---
Oct. 05, 2015 USD ($) | Aug. 31, 2013 USD ($) | Dec. 31, 2016 USD ($) property mortgage lender | Dec. 31, 2015 USD ($)
Debt Instrument [Line Items] |  |  |  |
Number of properties collateralized in mortgage notes payable | property |  |  | 94 |
Net book value of collateralized mortgage properties |  |  | $ 5,900,000 |
Number of long-term mortgages issued | mortgage |  |  | 7 |
Number of properties to issue collateralized mortgage notes payable | mortgage |  |  | 12 |
Number of mortgages repaid | mortgage |  |  | 7 |
Number of properties collateralized | mortgage |  |  | 16 |
Extension period subject to payment of fee | 1 year |  |  |
Fair value of mortgage notes payable outstanding |  |  | $ 445,400,000 |
Carrying value of debt |  |  | 509,395,000 | $ 525,332,000
Line of credit facility, maximum borrowing capacity |  | $ 100,000,000.0 | $ 150,000,000.0 |
Term of extended period |  | 1 year |  |
Basis spread reduction (as percent) |  |  | 0.25% |
Number of lenders added | lender |  |  | 3 |
Cost for modification of the credit facility agreement |  |  | $ 500,000 |
Borrowings under revolving credit facility, net |  |  | $ 39,225,000 | 44,591,000
Line of credit at an interest rate (as percent) |  |  | 3.00% |
Letters of credit, outstanding |  |  | $ 800,000 |
Weighted average interest rate on debt outstanding (as percent) |  |  | 4.48% |
5-Year Term Loan Facility [Member] |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Line of credit facility, maximum borrowing capacity |  |  | $ 25,000,000.0 |
Basis spread reduction (as percent) |  |  | 0.05% |
Line of Credit [Member] |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Line of credit facility, maximum borrowing capacity | $ 85,000,000.0 |  |  |
Borrowings under revolving credit facility, net |  |  | $ 64,700,000 |
Line of credit facility, maximum additional amount drawn |  |  | $ 30,800,000 |
Line of Credit [Member] | 5-Year Term Loan Facility [Member] |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Line of credit facility, maximum borrowing capacity | $ 25,000,000.0 |  |  |
Debt instrument term |  |  | 5 years |
Letter of Credit [Member] |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Weighted average interest rate on debt outstanding (as percent) |  |  | 2.25% |
Mortgage Notes Payable [Member] |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Number of mortgage notes payable | mortgage |  |  | 44 |
Number of properties collateralized in mortgage notes payable | property |  |  | 70 |
Net book value of collateralized mortgage properties |  |  | $ 647,600,000 |
Collateral |  |  | $ 8,900,000 |
Collateral (as percent) |  |  | 2.00% |
Carrying value of debt |  |  | $ 445,278,000 | $ 455,863,000
Weighted average interest rate on debt outstanding (as percent) |  |  | 4.69% |

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- Definition Line of credit facility optional extension period. + References No definition available. + Details
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- Definition Amount of long-term debt before deduction of unamortized discount or premium. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt, with initial maturities beyond one year or the normal operating cycle, if longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 20 -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 16 -Article 9 + Details
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- Definition Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
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- Definition The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.16) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.16) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19, 20, 22 -Article 5 + Details
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