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Subsequent Events - Additional Information (Details) - USD ($) | 1 Months Ended |  |  |  |
--- | --- | --- | --- | --- | ---
Jul. 30, 2018 | Jul. 23, 2018 | Jun. 30, 2018 | Apr. 18, 2018 | Dec. 31, 2017
Series D Preferred Stock | Subsequent event |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |
Gross proceeds of the offering | $ 1,600,000 |  |  |  |
Number of shares issued (in shares) | 83,430 |  |  |  |
Variable rate mortgage loans |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |
Carrying value |  |  | $ 61,590,000 | $ 13,000,000.0 | $ 69,302,000
Variable rate mortgage loans | Subsequent event |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |
Carrying value |  | $ 4,000,000 |  |  |

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- Definition Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt. + 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 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 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 + Details
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- Definition Proceeds from issuance of capital stock which provides for a specific dividend that is paid to the shareholders before any dividends to common stockholders and which takes precedence over common stockholders in the event of liquidation. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3255-108585 + Details
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- Definition Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event. + References No definition available. + Details
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