Shareholders' Equity, Noncontrolling Interests and Other Comprehensive Income - Summary of Change in Noncontrolling Interest (Parenthetical) (Details) - $ / shares	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Minority Interest [Line Items]
Distributions declared (in dollars per share)	$ 0.81	$ 0.78
Conversion of Common OP Units to Common Shares by limited partners of the Operating Partnership (in shares)	111,588	61,150
Operating Partnership, as General Partner or Managing Member
Minority Interest [Line Items]
Series A Preferred OP Units (in shares)	3,331,440		3,328,873
Operating Partnership, as General Partner or Managing Member | Series A Preferred Stock
Minority Interest [Line Items]
Series A Preferred OP Units (in shares)	188		188
Operating Partnership, as General Partner or Managing Member | Series C Preferred Stock
Minority Interest [Line Items]
Series A Preferred OP Units (in shares)	136,593		136,593
LTIP Units
Minority Interest [Line Items]
LTIP units outstanding (in shares)	2,547,002		2,274,147