Noncontrolling Interest - Operating Partnership/Limited Partners' Equity - Preferred Units (Details) (USD $)					3 Months Ended
	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2012 Series I-2 [Member]	Dec. 31, 2011 Series I-2 [Member]	Jun. 30, 2012 Unredeemed [Member] Series I-2 [Member]
Limited Partners' Capital Account - Preferred Units [Line Items]
Noncontrolling Interest in Operating Partnerships					$ 7,537,000
Preferred Units, Outstanding	1,290,000	9,740,000	301,483	301,483	301,000
Redeemable Preferred Units Liquidation Preference					$ 25
Preferred Stock Dividends Rate Percentage Or Per Dollar Amount					6.25%