Mortgage Notes Payable, Credit Facilities and Senior Notes - Carrying Value of the Company’s Unsecured Debt (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020	Dec. 20, 2019	Nov. 10, 2017	Jul. 26, 2016	Dec. 03, 2014	Dec. 09, 2013
Debt Instrument [Line Items]
Senior Notes	$ 945,231,000	$ 943,655,000
Term Loan Agreement
Debt Instrument [Line Items]
Principal amount	300,000,000	300,000,000	$ 300,000,000
Net unamortized deferred financing costs	(1,111,000)	(1,476,000)
Total	298,889,000	298,524,000
Senior Notes
Debt Instrument [Line Items]
Principal amount	950,000,000
Senior Notes | Senior Notes Due 2027
Debt Instrument [Line Items]
Principal amount	250,000,000	250,000,000		$ 250,000,000
Net unamortized deferred financing costs	(1,050,000)	(1,226,000)
Senior Notes	248,950,000	248,774,000
Senior Notes | Senior Notes Due 2026
Debt Instrument [Line Items]
Principal amount	200,000,000	200,000,000			$ 200,000,000
Net unamortized deferred financing costs	(366,000)	(443,000)
Senior Notes	199,634,000	199,557,000
Senior Notes | Senior Notes Due 2024
Debt Instrument [Line Items]
Principal amount	250,000,000	250,000,000				$ 250,000,000
Unamortized debt discount	(1,188,000)	(1,557,000)
Net unamortized deferred financing costs	(652,000)	(873,000)
Senior Notes	248,160,000	247,570,000
Senior Notes | Senior Notes Due 2023
Debt Instrument [Line Items]
Principal amount	250,000,000	250,000,000					$ 250,000,000
Unamortized debt discount	(998,000)	(1,468,000)
Net unamortized deferred financing costs	(515,000)	(778,000)
Senior Notes	$ 248,487,000	$ 247,754,000