Significant Credit and Revenue Concentration - Narrative (Details) |
3 Months Ended | 6 Months Ended | 12 Months Ended | |
|---|---|---|---|---|
|
Jun. 30, 2017
tenant
|
Jun. 30, 2016 |
Jun. 30, 2017
tenant
|
Dec. 31, 2016
Customer
tenant
|
|
| Revenue, Major Customer [Line Items] | ||||
| Number of tenants | 432 | 432 | 450 | |
| Revenues | Customer Concentration Risk | ||||
| Revenue, Major Customer [Line Items] | ||||
| Number of tenants | 0 | 0 | 0 | |
| Revenues | Minimum | Customer Concentration Risk | ||||
| Revenue, Major Customer [Line Items] | ||||
| Concentration risk (as a percent) | 4.00% | 4.00% | ||
| Shopko | Revenues | Customer Concentration Risk | ||||
| Revenue, Major Customer [Line Items] | ||||
| Concentration risk (as a percent) | 7.60% | 9.50% | ||
| Shopko | Total Assets | Customer Concentration Risk | ||||
| Revenue, Major Customer [Line Items] | ||||
| Concentration risk (as a percent) | 5.40% | 5.80% | ||
| Shopko | Real Estate Investment Portfolio | Customer Concentration Risk | ||||
| Revenue, Major Customer [Line Items] | ||||
| Concentration risk (as a percent) | 7.30% | 7.70% | ||