Financial Instruments and Fair Values - Schedule of the aggregate carrying value of debt and estimates of fair value (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swaps included in accounts payable and accrued expenses	$ 25,308	$ 8,849
Carrying Value | Revolving credit facility | Unsecured term loan facilities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	388,223	387,561
Carrying Value | Mortgage notes payable
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	948,769	775,929
Carrying Value | Senior unsecured notes | Senior unsecured notes - Series A, B, C, D, E, F, G and H
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	973,373	973,159
Carrying Value | Interest rate swaps
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swaps included in accounts payable and accrued expenses	25,308	8,849
Estimated Fair Value | Revolving credit facility | Unsecured term loan facilities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	390,000	390,000
Estimated Fair Value | Mortgage notes payable
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	960,933	808,294
Estimated Fair Value | Senior unsecured notes | Senior unsecured notes - Series A, B, C, D, E, F, G and H
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	994,389	1,039,857
Estimated Fair Value | Level 1 | Revolving credit facility | Unsecured term loan facilities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	0	0
Estimated Fair Value | Level 1 | Mortgage notes payable
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	0	0
Estimated Fair Value | Level 1 | Senior unsecured notes | Senior unsecured notes - Series A, B, C, D, E, F, G and H
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	0	0
Estimated Fair Value | Level 2 | Revolving credit facility | Unsecured term loan facilities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	0	0
Estimated Fair Value | Level 2 | Mortgage notes payable
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	0	0
Estimated Fair Value | Level 2 | Senior unsecured notes | Senior unsecured notes - Series A, B, C, D, E, F, G and H
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	0	0
Estimated Fair Value | Level 3 | Revolving credit facility | Unsecured term loan facilities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	390,000	390,000
Estimated Fair Value | Level 3 | Mortgage notes payable
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	960,933	808,294
Estimated Fair Value | Level 3 | Senior unsecured notes | Senior unsecured notes - Series A, B, C, D, E, F, G and H
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	994,389	1,039,857
Estimated Fair Value | Interest rate swaps
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swaps included in accounts payable and accrued expenses	25,308	8,849
Estimated Fair Value | Interest rate swaps | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swaps included in accounts payable and accrued expenses	0	0
Estimated Fair Value | Interest rate swaps | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swaps included in accounts payable and accrued expenses	25,308	8,849
Estimated Fair Value | Interest rate swaps | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swaps included in accounts payable and accrued expenses	$ 0	$ 0