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Face amount or stated value per share of common stock.

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Unrecognized cost of unvested share-based awards, other than options, awarded to employees as compensation.

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Amount of cash outflow in the form of ordinary dividends provided by the non-wholly owned subsidiary to noncontrolling interests.

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Share-Based Compensation - Narrative (Details)							3 Months Ended		9 Months Ended		12 Months Ended
Share-Based Compensation - Narrative (Details)	Aug. 18, 2016 USD ($) shares	Feb. 25, 2016 company	Jul. 13, 2015 USD ($) shares	Jun. 02, 2015 USD ($) $ / shares shares	Apr. 08, 2015 $ / shares	Apr. 07, 2015 shares	Sep. 30, 2016 USD ($) $ / shares shares	Sep. 30, 2015 USD ($)	Sep. 30, 2016 USD ($) $ / shares shares	Sep. 30, 2015 USD ($) shares	Dec. 31, 2015 $ / shares shares	Jun. 30, 2014 $ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, par value (usd per share) \| $ / shares					$ 0.01		$ 0.01		$ 0.01		$ 0.01	$ 0.01
Distributions paid related to LTIP Units \| $									$ 1,749,000	$ 321,000
Restricted Share Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum authorized amount as a percentage of shares authorized					10.00%
Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued in lieu of cash (shares)									0	0
Restricted Share Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual retainer payable, cash (percent)				50.00%
Annual retainer payable, restricted stock units (percent)				50.00%
Restricted Share Plan \| Independent Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual retainer payable \| $	$ 100,000		$ 100,000	$ 100,000
Annual retainer payable, cash (percent)	50.00%		50.00%
Restricted Share Plan \| Non-Executive Chair
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual retainer payable \| $	$ 100,000		$ 100,000	105,000
Restricted Share Plan \| Directors, Servicing on Committees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual retainer payable \| $				$ 30,000
OPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued during the period (shares)				9,041,801
Restricted share vesting period (years)									30 days
Compensation expense \| $							$ 1,200,000	$ 1,800,000	$ 2,100,000	$ 2,300,000
Award value, percent of market capitalization (percent)				5.00%
Requisite service period (years)				5 years					5 years
Distribution percent entitled to by LTIP holders							10.00%		10.00%
Distributions paid related to LTIP Units \| $							$ 200,000		$ 900,000
Number of companies (company) \| company		2
OPP \| Annual Period
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted share vesting period (years)				1 year
OPP \| Interim Period
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted share vesting period (years)				2 years
OPP \| Performance Period
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted share vesting period (years)				3 years
Stock Options \| Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)							500,000.0		500,000.0		500,000.0
Shares issued during the period (shares)									0		0
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)									32,907
Granted, weighted average issue price (usd per share) \| $ / shares									$ 7.52
Restricted Stock \| Restricted Share Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)						7,500,000.0
Shares granted automatically upon election to board of directors (in shares)						3,000
Restricted share vesting period (years)					5 years	5 years
Periodic vesting percentage						20.00%
Maximum authorized amount as a percentage of shares authorized						5.00%
Compensation expense \| $								$ 100,000		$ 100,000
Restricted Stock \| Director Stock Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted share vesting period (years)				5 years
Restricted Stock \| Restricted Share Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense \| $							$ 100,000		$ 300,000
Compensation costs not yet recognized \| $							$ 1,200,000		$ 1,200,000
Weighted average period of recognition (years)									4 years 18 days
Restricted Stock Units (RSUs) \| Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)				40,000
Granted, weighted average issue price (usd per share) \| $ / shares				$ 8.52
Restricted Stock Units (RSUs) \| Restricted Share Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted share vesting period (years)				3 years
Restricted Stock Units (RSUs) \| Restricted Share Plan \| Independent Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted share vesting period (years)	3 years		3 years
Annual retainer payable, restricted stock units (percent)	50.00%		50.00%
Granted (in shares)	8,642		7,352
Restricted Stock Units (RSUs) \| Restricted Share Plan \| Non-Executive Chair
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted share vesting period (years)	3 years		3 years
Annual retainer payable, restricted stock units (percent)	50.00%		50.00%
Granted (in shares)	6,981		5,882