Shareholders' Equity, Noncontrolling Interests and Other Comprehensive Income - Summary of Change in Noncontrolling Interest (Parenthetical) (Details) - $ / shares	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Minority Interest [Line Items]
Cash dividends declared per common share (in dollars per share)	$ 0.28	$ 0.27	$ 0.27	$ 0.27	$ 0.27	$ 0.26	$ 0.26	$ 0.26	$ 1.09	$ 1.05	$ 1.16
Conversion of Common OP Units to Common Shares by limited partners of the Operating Partnership (in shares)	117,978				81,453				117,978	81,453	351,250
Preferred shares converted to common stock (in shares)					5,000					5,000
Operating Partnership, as General Partner or Managing Member
Minority Interest [Line Items]
Series A Preferred OP Units (in shares)	3,329,640				3,328,873				3,329,640	3,328,873	3,308,875
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				188	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				136,593	136,593	136,593
LTIP Units
Minority Interest [Line Items]
LTIP units outstanding (in shares)	2,569,044				2,274,147				2,569,044	2,274,147	1,997,099