Noncontrolling Interest - Operating Partnership/Limited Partners' Equity - Preferred Units (Details) (USD $)					3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2013 Series I-2 [Member]	Dec. 31, 2012 Series I-2 [Member]	Mar. 31, 2013 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	1,290,000	301,483	301,483	301,000
Redeemable Preferred Units Liquidation Preference					$ 25
Preferred Stock Dividends Rate Percentage Or Per Dollar Amount					6.25%