Consolidated Statements of Equity (Unaudited) - USD ($)	Total	Preferred Stock	Common Stock	Capital in Excess of Par Value	Treasury Stock	Cumulative Net Income	Cumulative Dividends	Accumulated Other Comprehensive Income (Loss)	Other Equity	Noncontrolling Interests
Balances at beginning of period at Dec. 31, 2013	$ 11,756,331,000	$ 1,017,361,000	$ 289,461,000	$ 12,418,520,000	$ (21,263,000)	$ 2,329,869,000	$ (4,600,854,000)	$ (24,531,000)	$ 6,020,000	$ 341,748,000
Comprehensive income:
Net income (loss)	305,846,000					307,164,000				(1,318,000)
Other comprehensive income	(37,728,000)							(28,173,000)		(9,555,000)
Total comprehensive income	268,118,000
Net change in noncontrolling interests	(28,880,000)			(7,818,000)						(21,062,000)
Amounts related to issuance of common stock from dividend reinvestment and stock incentive plans, net of forfeitures	201,868,000		3,614,000	212,718,000	(13,978,000)				(486,000)
Proceeds from issuance of common stock	2,064,401,000		33,925,000	2,030,476,000
Conversion of preferred stock		(11,111,000)	233,000	10,878,000
Equity component of convertible debt	875,000		200,000	675,000
Option compensation expense	689,000								689,000
Cash dividends paid:
Common stock	(708,923,000)						(708,923,000)
Preferred Stock	(49,057,000)						(49,057,000)
Balances at end of period at Sep. 30, 2014	13,505,422,000	1,006,250,000	327,433,000	14,665,449,000	(35,241,000)	2,637,033,000	(5,358,834,000)	(52,704,000)	6,223,000	309,813,000
Balances at beginning of period at Dec. 31, 2014	13,473,049,000	1,006,250,000	328,835,000	14,740,712,000	(35,241,000)	2,842,022,000	(5,635,923,000)	(77,009,000)	5,507,000	297,896,000
Comprehensive income:
Net income (loss)	738,944,000					734,468,000				4,476,000
Other comprehensive income	(41,432,000)							(17,350,000)		(24,082,000)
Total comprehensive income	697,512,000
Net change in noncontrolling interests	209,014,000			(4,778,000)						213,792,000
Amounts related to issuance of common stock from dividend reinvestment and stock incentive plans, net of forfeitures	228,834,000		3,308,000	236,718,000	(9,095,000)				(2,097,000)
Proceeds from issuance of common stock	1,423,036,000		19,550,000	1,403,486,000
Conversion of preferred stock	0
Equity component of convertible debt	6,761,000		1,330,000	5,431,000
Option compensation expense	587,000								587,000
Cash dividends paid:
Common stock	(852,563,000)						(852,563,000)
Preferred Stock	(49,055,000)						(49,055,000)
Balances at end of period at Sep. 30, 2015	$ 15,137,175,000	$ 1,006,250,000	$ 353,023,000	$ 16,381,569,000	$ (44,336,000)	$ 3,576,490,000	$ (6,537,541,000)	$ (94,359,000)	$ 3,997,000	$ 492,082,000