Earnings Per Share - Potentially dilutive securities not included in calculating diluted earnings per share (Details) - shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total potentially dilutive securities	573,533	849,221	1,096,699
Common OP Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total potentially dilutive securities	531,112	771,708	1,019,186
Preferred OP Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total potentially dilutive securities	42,421	77,513	77,513