CONDENSED CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Thousands	Total	Series E Preferred Stock	Series F Preferred Stock	Total Stockholders’ Equity	Total Stockholders’ Equity Series E Preferred Stock	Total Stockholders’ Equity Series F Preferred Stock	Preferred Stock Series E Preferred Stock	Preferred Stock Series F Preferred Stock	Common Stock	Capital in Excess of Par Value	Retained Earnings (Deficit)	Retained Earnings (Deficit) Series E Preferred Stock	Retained Earnings (Deficit) Series F Preferred Stock	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests
Balance at Dec. 31, 2018	$ 4,154,605			$ 4,154,250			$ 287,500	$ 345,000	$ 1,616	$ 3,950,055	$ (424,225)			$ (5,696)	$ 355
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	80,033			80,023							80,023				10
Dividends declared and paid:
Preferred stock dividends declared and paid		$ (4,097)	$ (4,485)		$ (4,097)	$ (4,485)						$ (4,097)	$ (4,485)
Common stock dividends declared and paid	(75,406)			(75,406)					1	5,159	(80,566)
Issuance of common stock:
Director compensation	322			322						322
Stock purchase plan	119			119						119
Restricted shares, net of forfeitures	0			0					3	(3)
Stock issuance costs	(42)			(42)						(42)
Amortization of deferred compensation	2,225			2,225						2,225
Amortization of interest rate hedges	323			323										323
Fair value of forward starting swaps	0
Valuation adjustments – available-for-sale securities	116			116										116
Realized gain – available-for-sale securities	(1,331)			(1,331)										(1,331)
Other	505			505							505
Balance at Mar. 31, 2019	4,152,887			4,152,522			$ 287,500	345,000	1,620	3,957,835	(432,845)			(6,588)	365
Balance at Dec. 31, 2019	4,331,682			4,331,675				345,000	1,718	4,495,314	(499,229)			(11,128)	7
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	65,176			65,178							65,178				(2)
Dividends declared and paid:
Preferred stock dividends declared and paid			$ (4,485)			$ (4,485)							$ (4,485)
Common stock dividends declared and paid	(87,528)			(87,528)						620	(88,148)
Issuance of common stock:
Director compensation	298			298						298
Stock purchase plan	76			76						76
Restricted shares, net of forfeitures									3	(3)
Amortization of deferred compensation	2,950			2,950						2,950
Amortization of interest rate hedges	383			383										383
Fair value of forward starting swaps	(7,617)			(7,617)										(7,617)
Valuation adjustments – available-for-sale securities	0
Realized gain – available-for-sale securities	0
Balance at Mar. 31, 2020	$ 4,300,935			$ 4,300,930				$ 345,000	$ 1,721	$ 4,499,255	$ (526,684)			$ (18,362)	$ 5