Unconsolidated Joint Ventures (Details 13) (USD $) In Thousands, unless otherwise specified	6 Months Ended			0 Months Ended	6 Months Ended				6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Jun. 03, 2013 IN Retail Fund LLC properties	Jun. 30, 2013 IN Retail Fund LLC	Jun. 30, 2012 NARE/Inland North Aurora LLC	Jun. 30, 2013 Mortgages	Jun. 30, 2012 Mortgages IN Retail Fund LLC	Jun. 30, 2012 Mortgages NARE/Inland North Aurora LLC
Business Acquisition [Line Items]
Percentage ownership of property portfolio after acquisition of former joint venture				100.00%
Number of investment properties acquired				13
Investment properties, fair value				$ 396,000
Debt instrument, fair value								152,204
Unamortized mortgages premiums and discounts					3,742
Repayment of debt	863	9,388							10,000
Mortgages payable	541,254		412,361				537,512		30,537
Gain on extinguishment of debt									20,537
Gain (loss) on consolidation of investment properties						19,494
Summary of investment in joint ventures:
Investments in and advances to unconsolidated joint ventures prior to change in control transaction					28,328
Investments in and advances to unconsolidated joint ventures activity					(365)	10,131
Gain from change in control of investment properties				95,378	95,378	1,043
Cash paid					121,068	0
Net assets acquired					$ 244,409	$ 11,174