CONSOLIDATED STATEMENTS OF EQUITY (UNAUDITED) - USD ($) $ in Thousands	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, 2018	$ 15,586,599		$ 718,498	$ 384,465	$ 18,424,368	$ (68,499)	$ 6,121,534	$ (10,818,557)	$ (129,769)	$ 294	$ 954,265
Comprehensive income:
Net income (loss)	291,255						280,470				10,785
Other comprehensive income (loss)	(9,062)								(14,849)		5,787
Total comprehensive income	282,193
Net change in noncontrolling interests	(10,342)				(8,845)						(1,497)
Amounts related to stock incentive plans, net of forfeitures	1,521			120	7,420	(5,993)				(26)
Net proceeds from issuance of common stock	532,620			7,212	525,408
Conversion of preferred stock			(718,498)	12,712	705,786
Dividends paid:
Common stock dividends	(344,760)							(344,760)
Balances at end of period at Mar. 31, 2019	16,047,831		0	404,509	19,654,137	(74,492)	6,402,004	(11,163,317)	(144,618)	268	969,340
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Cumulative change in accounting principle (Note 2)	(5,212)						(5,212)
Adjusted balance	16,501,415		0	411,005	20,190,107	(78,955)	7,348,754	(12,223,534)	(112,157)	12	966,183
Balances at beginning of period at Dec. 31, 2019	16,506,627	[1]	0	411,005	20,190,107	(78,955)	7,353,966	(12,223,534)	(112,157)	12	966,183
Comprehensive income:
Net income (loss)	329,272						310,284				18,988
Other comprehensive income (loss)	(6,011)								15,944		(21,955)
Other comprehensive income (loss)	(6,465)
Total comprehensive income	323,261
Net change in noncontrolling interests	7,963				37,625						(29,662)
Amounts related to stock incentive plans, net of forfeitures	(1,166)			246	6,608	(8,020)
Net proceeds from issuance of common stock	590,865			6,975	583,890
Dividends paid:
Common stock dividends	(356,001)							(356,001)
Balances at end of period at Mar. 31, 2020	$ 17,066,337		$ 0	$ 418,226	$ 20,818,230	$ (86,975)	$ 7,659,038	$ (12,579,535)	$ (96,213)	$ 12	$ 933,554

[1] The consolidated balance sheet at December 31, 2019 has been derived from the audited financial statements at that date but does not include all of the information and footnotes required by U.S. generally accepted accounting principles for complete financial statements.