Mortgage Notes Payable, Credit Facilities and Senior Notes - Combined Aggregate Principal Maturities of Mortgage Notes Payable (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Principal Repayments
Long-term Debt	$ 299,191	$ 298,802
Mortgage Premium
Total	1,037	922
Total
Total mortgage notes payable	71,303	$ 62,156
Mortgage Notes Payable
Principal Repayments
2017	8,099
2018	18,900
2019	0
2020	0
2021	0
Thereafter	39,372
Long-term Debt	66,371
Scheduled Amortization
2017	689
2018	336
2019	157
2020	166
2021	282
Thereafter	2,682
Total	4,312
Mortgage Premium
2017	592
2018	204
2019	70
2020	70
2021	70
Thereafter	31
Total	1,037
Total
2017	9,380
2018	19,440
2019	227
2020	236
2021	352
Thereafter	42,085
Total mortgage notes payable	$ 71,720