Segment Reporting (Narratives) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013 segment	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]
Number of business segments									2
Segment Reporting Information Profit Loss
Operating expenses	$ 105,076	$ 91,625	$ 80,811	$ 75,194	$ 108,938	$ 82,133	$ 55,422	$ 52,998	$ 352,706	$ 299,491	$ 186,908
Reimbursed costs from affiliates									73,572	98,245	64,829
Other, net									52,472	87,921	85,632
Stock-based compensation expenses									37,280	26,241	17,750
Investment Management
Segment Reporting Information Profit Loss
Operating expenses									173,744	207,050	157,572
Other, net									768	3,878	2,695
Stock-based compensation expenses									36,965	26,030	17,750
Real Estate Ownership
Segment Reporting Information Profit Loss
Operating expenses									178,962	92,441	29,336
Other, net									51,704	84,043	82,937
CPA: 16 - Global | Real Estate Ownership
Segment Reporting Information Profit Loss
Percentage of total investment in REIT									6.00%
Operating expenses									5,000
CPA15 Merger | Real Estate Ownership
Segment Reporting Information Profit Loss
Operating expenses										31,700
International | Real Estate Ownership
Segment Reporting Information Profit Loss
Operating expenses									52,428	1,245	3,515
Other, net									3,299	6,602	6,173
International | Real Estate Ownership | Medica France, S.A.
Segment Reporting Information Profit Loss
Other, net										15,100
Domestic | Real Estate Ownership
Segment Reporting Information Profit Loss
Operating expenses									126,534	91,196	25,821
Other, net									$ 48,405	$ 77,441	$ 76,764