Condensed Consolidated Statement of Equity - USD ($)	Total	At the Market Program [Member]	Stockholders' Equity, Total [Member]		Stockholders' Equity, Total [Member] At the Market Program [Member]	Common Stock [Member]	Common Stock [Member] At the Market Program [Member]	Preferred Stock [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member] At the Market Program [Member]	Accumulated Foreign Currency Adjustment Attributable to Parent [Member]		Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]		Dividends/Distributions in Excess of Earnings [Member]	Noncontrolling Interest [Member]
Balance, shares Period Start at Dec. 31, 2014						333,856,632
Balance, value Period Start at Dec. 31, 2014			$ 6,737,228,000			$ 3,339,000		$ 98,000	$ 9,512,396,000		$ 34,545,000		$ (18,725,000)		$ (2,815,428,000)	$ 21,003,000
Preferred Stock, Shares Outstanding Period Start at Dec. 31, 2014								9,775,000
Stock-based compensation related activity, net of forfeitures, value			20,311,000			$ 2,000			20,309,000		0		0		0	0
Stock-based compensation related activity, net of forfeitures, shares						238,416
Purchases and retirement of capital stock, value			(29,372,000)			$ (2,000)			(29,370,000)		0		0		0	0
Proceeds from Issuance of Common Stock	$ 0
Purchases and retirement of capital stock, shares						(333,089)
Other comprehensive income (loss)	(8,771,000)		(8,771,000)	[1]		$ 0			0		(15,007,000)	[1]	7,491,000	[1]	0	(1,255,000)	[1]
Common stock dividends/distributions			(274,718,000)												(274,718,000)
Preferred stock dividends	(10,997,000)		(10,997,000)												(10,997,000)
Net income (loss)	$ 125,112,000		125,112,000			$ 0			0		0		0		122,787,000	2,325,000
Balance, shares Period End at Mar. 31, 2015						333,761,959
Balance, value Period End at Mar. 31, 2015			6,558,793,000			$ 3,339,000		$ 98,000	9,503,335,000		19,538,000		(11,234,000)		(2,978,356,000)	22,073,000
Preferred Stock, Shares Outstanding Period End at Mar. 31, 2015								9,775,000
Balance, shares Period Start at Dec. 31, 2015	333,771,660					333,771,660
Balance, value Period Start at Dec. 31, 2015	$ 7,089,221,000		7,089,221,000			$ 3,338,000		$ 98,000	9,548,580,000		(4,398,000)		0		(2,458,397,000)	0
Preferred Stock, Shares Outstanding Period Start at Dec. 31, 2015	9,775,000							9,775,000
Stock-based compensation related activity, net of forfeitures, value			26,875,000			$ 2,000			26,873,000		0		0		0	0
Stock-based compensation related activity, net of forfeitures, shares						243,110
Purchases and retirement of capital stock, value			(24,354,000)			$ (3,000)			(24,351,000)		0		0		0	0
Stock Issued During Period, Shares, New Issues							3,828,064
Proceeds from Issuance of Common Stock	$ 323,798,000	$ 323,798,000			$ (323,798,000)		$ (38,000)			$ (323,760,000)
Purchases and retirement of capital stock, shares						(283,116)
Other comprehensive income (loss)	(579,000)		(579,000)	[2]		$ 0			0		(579,000)	[2]	0	[2]	0	0	[2]
Common stock dividends/distributions			(298,810,000)												(298,810,000)
Preferred stock dividends	(10,997,000)		(10,997,000)												(10,997,000)
Net income (loss)	$ 47,840,000		47,840,000			$ 0			0		0		0		47,840,000	0
Balance, shares Period End at Mar. 31, 2016	337,559,718					337,559,718
Balance, value Period End at Mar. 31, 2016	$ 7,152,994,000		$ 7,152,994,000			$ 3,375,000		$ 98,000	$ 9,874,862,000		$ (4,977,000)		$ 0		$ (2,720,364,000)	$ 0
Preferred Stock, Shares Outstanding Period End at Mar. 31, 2016	9,775,000							9,775,000

[1] See the condensed statement of operations and other comprehensive income (loss) for the components of "other comprehensive income (loss)" and note 4 with respect to the reclassification adjustments.

[2] See the condensed statement of operations and other comprehensive income (loss) for the components of "other comprehensive income (loss)."