| Schedule of Long-term Debt Instruments [Table Text Block] |
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | $ | 215,000 | | | $ | 215,000 | | | | | | (1,981 | ) | | | (2,162 | ) | Unamortized debt issuance costs | | | (3,349 | ) | | | (3,656 | ) | Senior unsecured notes less unamortized discount and debt issuance costs | | | 209,670 | | | | 209,182 | | Revolving credit facility | | | - | | | | - | | Mortgage loan obligations | | | 22,023 | | | | 31,607 | | Unamortized premium - mortgage loan obligations | | | 193 | | | | 383 | | Unamortized debt issuance costs - mortgage loan obligations | | | (160 | ) | | | (283 | ) | Capital lease obligations | | | 190 | | | | 206 | | | | | | 231,916 | | | | 241,095 | | | | | | 1,867 | | | | 10,078 | | | | | $ | 230,049 | | | $ | 231,017 | | |