Net Investments in Properties (Narratives) (Details) (USD $)	0 Months Ended	12 Months Ended						12 Months Ended													12 Months Ended		0 Months Ended	12 Months Ended		0 Months Ended			12 Months Ended			12 Months Ended				12 Months Ended
	May 02, 2011	Dec. 31, 2013 lease property	Dec. 31, 2012	Dec. 31, 2011	Jan. 31, 2014 property	Nov. 30, 2013	Dec. 31, 2013 Carrefour France SAS	Dec. 31, 2013 Intangible	Dec. 31, 2012 Intangible	Dec. 31, 2011 Intangible	Dec. 31, 2013 Real Estate	Dec. 31, 2012 Real Estate	Dec. 31, 2011 Real Estate	Dec. 31, 2013 Finance Leases	Dec. 31, 2012 Finance Leases	Dec. 31, 2011 Finance Leases	Dec. 31, 2013 Assets held-for-sale	Dec. 31, 2012 Assets held-for-sale	Dec. 31, 2011 Assets held-for-sale	Dec. 31, 2013 Hotel property	Dec. 31, 2012 CPA: 15	Sep. 28, 2012 CPA: 15 property	May 02, 2011 CPA 14/16 Merger	Dec. 31, 2013 Real estate	Dec. 31, 2012 Real estate	Sep. 13, 2012 Real estate Walgreens Co.	Dec. 31, 2013 Operating real estate property	Dec. 31, 2012 Operating real estate property	Dec. 31, 2013 Business combination	Dec. 31, 2011 Domestic	Dec. 31, 2013 Domestic property	Dec. 31, 2013 Domestic Real estate Office	Dec. 31, 2013 Domestic Business combination Office	Dec. 31, 2013 Domestic Business combination Office Building	Dec. 31, 2013 International property	Dec. 31, 2013 International Real estate Research and development facility	Dec. 31, 2013 International Business combination Office	Dec. 31, 2013 International Business combination Logistic facility	Dec. 31, 2013 International Build to Suit Transaction Office	Dec. 31, 2011 Operating lease
Real Estate Properties
Depreciation		$ 61,800,000	$ 25,700,000	$ 15,000,000
Number of real estate properties		418																				305						21
Foreign Currency Translation
Increase decrease in foreign currency exchange rate		4.20%
Foreign currency exchange rate		1.3768	1.3218
Foreign currency translation adjustments		21,835,000	7,809,000	(1,796,000)																				25,500,000
Assets Held For Sale
Number of leases restructuring		6
Number of properties held for sale																															12				1
Reclassification from real estate								(24,423,000)	(852,000)	0	13,952,000	0	17,651,000	(13,952,000)	0	(17,651,000)	91,747,000	14,868,000	0
Assets held for sale		86,823,000	1,445,000					24,423,000			62,400,000
Net investments in properties		2,353,391,000	2,298,123,000				18,700,000														1,762,872,000			2,348,249,000	2,218,413,000		5,142,000	79,710,000
Number of properties sold					6															1							19
Investments in real estate
Investment purchase price																								124,400,000		24,800,000			157,700,000			72,400,000	33,600,000	25,500,000		52,100,000	63,300,000	35,300,000	65,000,000
Contractual obligation funded																																							3,900,000
Construction costs																																							5,600,000
Commitment for Tenant Improvement																																	5,200,000
Acquired finite-lived intangible asset, acquisition		100,674,000																						26,500,000		6,600,000
Measurement period adjustment																										5,300,000
Proceeds from mortgage financing		115,567,000	23,750,000	45,491,000																										29,000,000
Acquisition-related cost	31,800,000																							1,500,000		200,000
Fair value of business acquired						13,748,000															1,663,363,000		174,800,000
Acquisition costs, expensed																													4,200,000
Real estate under construction																								9,521,000	0
Land aquired																													17,200,000
Buildings acquired																													99,000,000
Acquired finite-lived intangible asset, business combination																					695,310,000	695,310,000	40,800,000						41,500,000
Investments in real estate						33,625,000																1,762,872,000	90,200,000
Non-recourse debt		1,492,410,000	1,715,397,000																		1,350,755,000	1,350,755,000	117,100,000
Gain on change in control of interests		0	20,744,000	27,859,000																	14,700,000		27,900,000
Out of period adjustment				$ 200,000																																				$ 17,900,000