SHAREHOLDERS' EQUITY AND NONCONTROLLING INTERESTS Common Shares (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Class of Stock [Line Items]
Proceeds from Issuance of Common Stock	$ 45.0
Common Stock [Member]
Class of Stock [Line Items]
Issuance of Common Shares, net of issuance costs (in Shares)	2,250,000		5,750,000
Restricted Stock [Member]
Class of Stock [Line Items]
Restricted Stock, Shares Canceled for Tax Withholding For Share Based Compensation	40,254
LTIP Units and Restricted Stock [Member]
Class of Stock [Line Items]
Allocated Share-based Compensation Expense	$ 4.0	$ 3.8	$ 3.7