Segment Reporting (Narratives) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014 segment	Mar. 31, 2013
Segment Reporting Information [Line Items]
Number of business segments	2
Segment Reporting Information Profit Loss
Operating expenses	$ 171,742	$ 75,194
Reimbursable costs from affiliates	39,732	11,968
Stock-based compensation expenses	7,045	9,149
Real Estate Ownership
Segment Reporting Information Profit Loss
Operating expenses	107,362	39,898
Investment Management
Segment Reporting Information Profit Loss
Operating expenses	64,380	35,296
Stock-based compensation expenses	6,800	9,000
CPA: 16 - Global | Real Estate Ownership
Segment Reporting Information Profit Loss
Operating expenses	$ 29,500