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Mortgage Notes Payable and Credit Facility - Mortgages Notes Payable (Detail) $ in Thousands |  | 3 Months Ended |
--- | --- | --- | ---
Oct. 27, 2017 | Mar. 31, 2019 USD ($) property | Mar. 31, 2018 USD ($) property | Dec. 27, 2018 property
Debt Instrument [Line Items] |  |  |  |
Debt Repaid |  | $ 6,692 | $ 19,092 |
Number of properties acquired | property |  | 2 | 1 |
LIBOR |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Spread on LIBOR (as percent) | 2.75% |  |  |
Fixed rate mortgage loans |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Debt Repaid |  | $ 3,530 |  |
Stated interest rate (as percent) |  | 3.86% |  |
New fixed rate mortgage notes payable |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Stated interest rate (as percent) |  | 4.70% |  |
Term of debt |  | 7 years |  |
Aggregate Fixed Rate Debt Issued or Assumed |  | $ 10,600 |  |
Number of properties acquired | property |  |  |  | 1
New fixed rate mortgage notes payable | LIBOR | Weighted average |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Spread on LIBOR (as percent) |  | 1.80% |  |
Variable rate mortgage loans debt extended |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Term of debt |  | 3 years |  |
Variable rate mortgage loans debt extended | LIBOR | Weighted average |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Spread on LIBOR (as percent) |  | 1.80% |  |

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