Fair Value Measurements (Narratives) (Details) (USD $) In Thousands, unless otherwise specified			3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2014 CPA: 16 - Global Maximum	Mar. 31, 2014 CPA: 16 - Global Minimum	Mar. 31, 2014 Redeemable noncontrolling interest Maximum	Mar. 31, 2014 Redeemable noncontrolling interest Minimum	Mar. 31, 2014 Deferred acquisition fees receivable Maximum	Mar. 31, 2014 Deferred acquisition fees receivable Minimum	Mar. 31, 2014 Fair Value, Measurements, Nonrecurring Level 3	Mar. 31, 2013 Fair Value, Measurements, Nonrecurring Level 3	Mar. 31, 2014 Fair Value, Measurements, Nonrecurring Level 3 Continuing Operations	Mar. 31, 2013 Fair Value, Measurements, Nonrecurring Level 3 Continuing Operations	Mar. 31, 2014 Fair Value, Measurements, Nonrecurring Level 3 Continuing Operations Equity method investments	Mar. 31, 2013 Fair Value, Measurements, Nonrecurring Level 3 Continuing Operations Equity method investments	Mar. 31, 2014 Fair Value, Measurements, Nonrecurring Level 3 Discontinued Operations	Mar. 31, 2013 Fair Value, Measurements, Nonrecurring Level 3 Discontinued Operations
Fair value inputs
Lack of marketability					30.00%	20.00%
Discount rate			15.75%	12.75%	26.00%	22.00%
EBITDA Multiple					5	3
Gen and admin to assets ratio			0.45%	0.35%
Leverage adjusted unsecured spread							3.55%	1.20%
Illiquidity Adjustment							1.00%	0.50%
Impairment charges on properties									$ 735	$ 5,963	$ 735	$ 2,684	$ 735	$ 2,684	$ 0	$ 3,279
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	$ 5,127	$ 3,780