Consolidated Statements of Shareholders' Equity (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common Stock	Additional Paid-in Capital	Accumulated Distributions in Excess of Net Income	Accumulated Other Comprehensive Loss	Treasury Stock	Noncontrolling Interest
Balance at Dec. 31, 2010	$ 317,224	$ 4,657	$ 574,994	$ (205,021)	$ 0	$ (58,446)	$ 1,040
Balance (in shares) at Dec. 31, 2010		41,380,205
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to AERC	5,328			5,328
Other comprehensive income:
Change in fair value of hedge intstruments	(405)				(405)
Noncontrolling interest	(11)						(11)
Redemption of operating partnership units	0
Share-based compensation	3,290		1,795	5		1,490
Purchase of common shares (in shares)		(55,168)
Purchase of common shares	(857)					(857)
Issuance of common shares (in shares)		788,676
Issuance of common shares	13,300		6,278			7,022
Option exercises (in shares)		80,456
Option exercises	810		105			705
Restricted share activity, net		136,730
Cash dividends declared and paid to common shareholders	(28,857)			(28,857)
Balance at Dec. 31, 2011	309,822	4,657	583,172	(228,545)	(405)	(50,086)	1,029
Balance (in shares) at Dec. 31, 2011		42,330,899
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to AERC	30,592			30,592
Other comprehensive income:
Change in fair value of hedge intstruments	(2,529)				(2,529)
Noncontrolling interest cash contribution	350						350
Noncontrolling interest	(35)
Redemption of operating partnership units	0
Net (loss) income from noncontrolling interests	35						(35)
Share-based compensation	4,297		2,379	2		1,916
Purchase of common shares (in shares)		(59,458)
Purchase of common shares	(959)					(959)
Issuance of common shares (in shares)	2,921,667
Issuance of common shares (in shares)	3,403,333	7,066,166
Issuance of common shares	98,149	296	48,763			49,090
Option exercises (in shares)		35,000
Option exercises	312		273			39
Restricted share activity, net		154,032
Cash dividends declared and paid to common shareholders	(35,257)			(35,257)
Balance at Dec. 31, 2012	404,742	4,953	634,587	(233,208)	(2,934)	0	1,344
Balance (in shares) at Dec. 31, 2012		49,526,639
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to AERC	61,250			61,250
Other comprehensive income:
Change in fair value of hedge intstruments	2,232				2,232
Redemption of operating partnership units	355		355
Net (loss) income from noncontrolling interests	4,541		3,547				994
Share-based compensation	5,478	70	5,406	2		0
Purchase of common shares (in shares)		(162,399)
Purchase of common shares	(2,618)					(2,618)
Issuance of common shares (in shares)		7,176,107
Issuance of common shares	116,751	716	116,029			6
Option exercises (in shares)	259,164	259,164
Option exercises	2,470	21	1,752			697
Restricted share activity, net		676,681
Cash dividends declared and paid to common shareholders	(41,319)			(41,319)
Balance at Dec. 31, 2013	$ 544,800	$ 5,760	$ 754,582	$ (213,275)	$ (702)	$ (1,915)	$ 350
Balance (in shares) at Dec. 31, 2013		57,476,192