Supplemental Disclosures of Cash Flow Information (Details) (USD $)	3 Months Ended
	Mar. 31, 2013 item	Mar. 31, 2012	Mar. 31, 2013 ARCT	Jan. 22, 2013 ARCT
Acquisition of American Realty Capital Trust, Inc.
Real estate investments and related intangible assets			$ 3,200,000,000
Other assets			21,100,000	42,570,000
Lines of credit payable			317,207,000	317,207,000
Term loan			235,000,000	235,000,000
Other liabilities			24,790,000	24,790,000
Mortgage notes payable			539,000,000	538,960,000
Acquired lease intangible liabilities			76,000,000	76,041,000
Noncontrolling interests			14,000,000
Interest paid	56,200,000	50,500,000
Interest capitalized to properties under development	229,000	145,000
Income taxes paid	901,000	588,000
Non-cash investing and financing activities
Share-based compensation expense	3,845,000	2,956,000
Number of acquired properties with assumed mortgages (excluding ARCT)	5
Mortgages assumed	48,200,000
Net premiums recorded on mortgages assumed	4,200,000
Increase in real estate	3,100,000
Decrease in acquired lease intangible assets	2,400,000
Increase in acquired lease intangible liabilities	712,000
Land acquired as a portion of a development property	750,000
Real estate acquired in exchange of properties	523,000
Increase in buildings and improvements and accounts payable		$ 2,800,000