Fair Value Measurements - Narrative (Details) - Property |
9 Months Ended | 12 Months Ended |
|---|---|---|
Sep. 30, 2016 |
Dec. 31, 2015 |
|
| Fair Value Disclosures [Abstract] | ||
| Impaired long-lived assets held and used, properties | 7 | 18 |
| Impaired long-lived assets held and used, properties estimating fair values on comparable properties | 13 |