Derivative Instruments - Summary of Interest Rate Swap Positions (Details) |
9 Months Ended |
|---|---|
|
Sep. 30, 2018
USD ($)
| |
| Minimum | |
| LIBOR-Based Debt: | |
| Margin on variable-rate debt | 0.30% |
| Maximum | |
| LIBOR-Based Debt: | |
| Margin on variable-rate debt | 2.75% |
| U.S. Dollar-denominated interest rate swap 1 | |
| LIBOR-Based Debt: | |
| Notional Amount | $ 104,133,000 |
| Fair Value / Carrying Amount of Asset | $ 1,770,000 |
| Remaining Term | 2 years 3 months 18 days |
| Fixed Interest Rate | 1.46% |
| U.S. Dollar-denominated interest rate swap 2 | |
| LIBOR-Based Debt: | |
| Notional Amount | $ 150,000,000 |
| Fair Value / Carrying Amount of Asset | $ 4,720,000 |
| Remaining Term | 2 years 3 months 18 days |
| Fixed Interest Rate | 1.55% |
| U.S. Dollar-denominated interest rate swap 3 | |
| LIBOR-Based Debt: | |
| Notional Amount | $ 50,000,000 |
| Fair Value / Carrying Amount of Asset | $ 2,014,000 |
| Remaining Term | 2 years 3 months 18 days |
| Fixed Interest Rate | 1.16% |