Redeemable Noncontrolling Interests (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Redeemable Noncontrolling Interest Units Table [Abstract]
Redeemable Noncontrolling Interest, Equity, Common, Carrying Amount	$ 1,242,895		$ 1,242,895		$ 1,223,793
Redeemable Noncontrolling Interests Rollforward [Abstract]
Reedemable Noncontrolling Interest, Beginning Balance			1,229,221	$ 1,337,780
Net income	4,366	$ 12,704	11,410	28,189
Other comprehensive income (loss)			2,326	(3,082)
Distributions			(23,582)	(22,502)
Other, net			26,814	31,478
Reedemable Noncontrolling Interest, Ending Balance	1,248,323	$ 1,113,885	1,248,323	1,113,885
Common Class A [Member]
Redeemable Noncontrolling Interest Units Table [Abstract]
Redeemable Noncontrolling Interest, Equity, Common, Carrying Amount	1,242,895		1,242,895		1,223,793
Redeemable Noncontrolling Interests Rollforward [Abstract]
Redemption of Class A units for common shares, at redemption value			(28,126)	(46,693)
Adjustments to carry redeemable Class A units at redemption value			30,260	(295,713)
Issuance of units				80,000
Series D17 Cumulative Redeemable Preferred Unit [Member]
Redeemable Noncontrolling Interests Rollforward [Abstract]
Issuance of units				$ 4,428
Cumulative Redeemable Preferred Unit [Member]
Redeemable Noncontrolling Interests Additional Disclosure [Abstract]
Fair value of Series G1 through G4 convertible preferred units and Series D-13 cumulative redeemable preferred units	$ 50,561		$ 50,561		$ 50,561