Financial Instruments and Fair Values - Summary of the Carrying and Estimated Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swaps included in accounts payable and accrued expenses	$ 11,947	$ 5,591
Carrying Value | Mortgages
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	724,312	759,016
Carrying Value | Exchangeable notes | Senior unsecured notes - exchangeable
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	243,106	241,474
Carrying Value | Senior notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	348,967	348,914
Estimated Fair Value | Mortgages
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	712,213	755,640
Estimated Fair Value | Exchangeable notes | Senior unsecured notes - exchangeable
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	282,878	282,435
Estimated Fair Value | Senior notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	345,258	339,274
Level 1 | Estimated Fair Value | Mortgages
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	0	0
Level 1 | Estimated Fair Value | Exchangeable notes | Senior unsecured notes - exchangeable
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	0	0
Level 1 | Estimated Fair Value | Senior notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	0	0
Level 2 | Estimated Fair Value | Mortgages
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	0	0
Level 2 | Estimated Fair Value | Exchangeable notes | Senior unsecured notes - exchangeable
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	282,878	282,435
Level 2 | Estimated Fair Value | Senior notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	0	0
Level 3 | Estimated Fair Value | Mortgages
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	712,213	755,640
Level 3 | Estimated Fair Value | Exchangeable notes | Senior unsecured notes - exchangeable
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	0	0
Level 3 | Estimated Fair Value | Senior notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	345,258	339,274
Unsecured term loan facility | Carrying Value | Term loan facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	263,114	262,927
Unsecured term loan facility | Estimated Fair Value | Term loan facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	265,000	265,000
Unsecured term loan facility | Level 1 | Estimated Fair Value | Term loan facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	0	0
Unsecured term loan facility | Level 2 | Estimated Fair Value | Term loan facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	0	0
Unsecured term loan facility | Level 3 | Estimated Fair Value | Term loan facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	265,000	265,000
Interest rate swaps
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swaps included in accounts payable and accrued expenses	12,000
Interest rate swaps | Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swaps included in prepaid expenses and other assets	0	614
Interest rate swaps included in accounts payable and accrued expenses	11,947	5,591
Interest rate swaps | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swaps included in prepaid expenses and other assets	0	614
Interest rate swaps included in accounts payable and accrued expenses	11,947	5,591
Interest rate swaps | Level 1 | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swaps included in prepaid expenses and other assets	0	0
Interest rate swaps included in accounts payable and accrued expenses	0	0
Interest rate swaps | Level 2 | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swaps included in prepaid expenses and other assets	0	614
Interest rate swaps included in accounts payable and accrued expenses	11,947	5,591
Interest rate swaps | Level 3 | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swaps included in prepaid expenses and other assets	0	0
Interest rate swaps included in accounts payable and accrued expenses	$ 0	$ 0