Discontinued Operations (Narratives) (Details) (USD $)	3 Months Ended	6 Months Ended			6 Months Ended			12 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2013	Jun. 30, 2013	Dec. 31, 2012 property	Jun. 30, 2013 Affiliate	Jun. 30, 2013 CPA15 Merger Affiliate	Jun. 30, 2013 Domestic property	Jun. 30, 2012 Domestic property	Dec. 31, 2012 Domestic	Jun. 30, 2013 Domestic CPA15 Merger property	Dec. 31, 2012 Domestic Five Properties	Dec. 31, 2011 Domestic Five Properties
Discontinued Operation Additional Disclosures
Properties sold			9			4	5		2
Proceeds from the sale of properties						$ 15,100,000	$ 25,200,000
Gain (loss) on sale of property						1,100,000	(500,000)
Impairment recognized on asset to be disposed								200,000	3,500,000	3,100,000	6,900,000
Payment of mortgage obligation						5,700,000
Gain on extinguishment of debt	13,000	84,000				100,000
Lease termination income									2,600,000
Impairment Of Long Lived Assets To Be Disposed Of		392,000
Allocation of goodwill to properties sold within the reporting unit		729,000
Anticipated proceeds from sales of asset					$ 16,400,000				$ 7,300,000
Jointly Owned Investments, Ownership Percentage	44.00%	44.00%		56.00%