Condensed Consolidated Statement of Equity (Unaudited) (USD $) In Thousands, except Share data, unless otherwise specified	Series H Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Distributions in Excess of Accumulated Earnings [Member]	Accumulated Other Comprehensive Loss, Net [Member]	Noncontrolling Interest [Member]	Total
Balances at Dec. 31, 2013	$ 73,750	$ 4	$ 2,345,763	$ (474,426)	$ (60,472)	$ 113,619	$ 1,998,238
Balances (in shares) at Dec. 31, 2013	2,950,000	37,421,000
Net income	0	0	0	80,341	0	8,971	89,312
Reversal of unrealized gains upon the sale of marketable securities	0	0	0	0	(841)	(45)	(886)
Changes in fair value of derivatives and amortization of swap settlements	0	0	0	0	7,426	306	7,732
Changes in fair value of marketable securities	0	0	0	0	2,479	112	2,591
Issuance of common stock under:
Stock Consideration in the Merger, net	0	2	3,777,644	0	0	0	3,777,646
Stock Consideration in the Merger, net (in shares)		23,093,000
Stock option and restricted stock plans	0	0	6,511	0	0	0	6,511
Stock option and restricted stock plans shares (in shares)	0	154,000
Equity distribution agreements, net	0	0	449,499	0	0	0	449,499
Equity distribution agreements, net (in shares)	0	2,527,000
Equity based compensation costs	0	0	5,756	0	0	1,672	7,428
Reclassification of noncontrolling interest to redeemable noncontrolling interest	0	0	(19,823)	0	0	1,067	(20,890)
Changes in value of redemption value of redeemable non-controlling Interest			2,126				2,126
Conversion of Series G preferred stock		0	4,349	0	0	0	4,349
Conversion of Series G preferred stock (in shares)		34,000
Contributions from noncontrolling interest	0	0		0	0	1,419,816	1,419,816
Retirement of noncontrolling interest	0	0	0	0	0	(1,419,816)	(1,419,816)
Distributions to noncontrolling interest	0	0	0	0	0	(12,821)	(12,821)
Redemptions of noncontrolling interest	0	0	(2,383)	0	0	(596)	(2,979)
Common and preferred stock dividends	0	0		(214,413)	0	0	(214,413)
Balances at Sep. 30, 2014	73,750	6	6,569,442	(608,498)	(51,408)	110,151	6,093,443
Balances (in shares) at Sep. 30, 2014	2,950,000	63,229,000
Balances at Jun. 30, 2014
Net income							58,684
Issuance of common stock under:
Equity distribution agreements, net (in shares)		801,909
Balances at Sep. 30, 2014		$ 6					$ 6,093,443
Balances (in shares) at Sep. 30, 2014		63,229,000