CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Thousands	Omega OP Total Stockholders' Equity [Member]	Omega OP Accumulated Other Comprehensive Loss	Omega OP Noncontrolling Interest	Omega OP	Total Stockholders' Equity [Member] Scenario, Previously Reported [Member]	Total Stockholders' Equity [Member]	Common Stock Scenario, Previously Reported [Member]	Common Stock	Additional Paid-in Capital Scenario, Previously Reported [Member]	Additional Paid-in Capital	Cumulative Net Earnings Scenario, Previously Reported [Member]	Cumulative Net Earnings	Cumulative Dividends Scenario, Previously Reported [Member]	Cumulative Dividends	Accumulated Other Comprehensive Loss Scenario, Previously Reported [Member]	Accumulated Other Comprehensive Loss	Noncontrolling Interest Scenario, Previously Reported [Member]	Noncontrolling Interest	Scenario, Previously Reported [Member]	Total
Beginning balance at Dec. 31, 2016						$ 3,858,745		$ 19,614		$ 4,861,408		$ 1,738,937		$ (2,707,387)		$ (53,827)		$ 353,241		$ 4,211,986
Increase (Decrease) In Stockholders' Equity [Roll Forward]
Grant of restricted stock to company directors								3		(3)
Stock-based compensation expense						15,212				15,212										15,212
Vesting/exercising of equity compensation plan						(2,143)		12		(2,155)										(2,143)
Dividend reinvestment plan						36,722		120		36,602										36,722
Grant of stock as payment of directors fees						150		1		149										150
Deferred compensation directors						108				108										108
Equity Shelf Program						22,120		72		22,048										22,120
Common dividends declared						(502,861)								(502,861)						(502,861)
Conversion of Omega OP Units to common stock						2,942		9		2,933										2,942
Redemption of Omega OP Units to common stock																		(2,990)		(2,990)
Omega OP Units distributions																		(22,626)		(22,626)
Comprehensive income:
Foreign currency translation	$ 21,845			$ 21,845		20,916										20,916		929		21,845
Cash flow hedges	2,883			2,883		2,761										2,761		122		2,883
Net income	104,910			104,910		100,419						100,419						4,491		104,910
Total comprehensive income	129,638			129,638																129,638
Balance , ending at Dec. 31, 2017		$ (31,640)			$ 3,555,091	3,564,668	$ 19,831	19,831	$ 4,936,302	4,936,302	$ 1,839,356	1,848,933	$ (3,210,248)	(3,210,248)	$ (30,150)	(30,150)	$ 333,167	333,590	$ 3,888,258	3,898,258
Increase (Decrease) In Stockholders' Equity [Roll Forward]
Cumulative effect of accounting change	10,000			10,000		9,577						9,577						423		10,000
Grant of restricted stock to company directors								4		(4)
Stock-based compensation expense						15,987				15,987										15,987
Vesting/exercising of equity compensation plan, net of tax withholdings						(1,654)		9		(1,663)										(1,654)
Dividend reinvestment plan						46,801		155		46,646										46,801
Deferred compensation directors						253		3		250										253
Equity Shelf Program						75,532		228		75,304										75,532
Common dividends declared						(528,949)								(528,949)						(528,949)
Conversion of Omega OP Units to common stock						1,727		5		1,722										1,727
Redemption of Omega OP Units to common stock																		(1,861)		(1,861)
Omega OP Units distributions																		(23,493)		(23,493)
Comprehensive income:
Foreign currency translation	(14,532)			(14,532)		(13,924)										(13,924)		(608)		(14,532)
Cash flow hedges	2,531			2,531		2,422										2,422		109		2,531
Net income	293,884			293,884		281,578						281,578						12,306		293,884
Total comprehensive income	281,883			281,883																281,883
Balance , ending at Dec. 31, 2018		(43,640)				3,444,441		20,235		5,074,544		2,130,511		(3,739,197)		(41,652)		320,043		3,764,484
Increase (Decrease) In Stockholders' Equity [Roll Forward]
Cumulative effect of accounting change	(8,490)			(8,490)
Grant of restricted stock to company directors								2		(2)
Stock-based compensation expense						14,871				14,871										14,871
Vesting/exercising of equity compensation plan, net of tax withholdings						(4,318)		15		(4,333)										(4,318)
Dividend reinvestment plan						115,051		304		114,747										115,051
Deferred compensation directors						222				222										222
Equity Shelf Program						108,996		313		108,683										108,996
Issuance of common stock - merger-related						281,628		748		280,880										281,628
Issuance of common stock						295,867		750		295,117										295,867
Common dividends declared						(564,349)								(564,349)						(564,349)
Vesting/exercising of Omega OP Units						(6,648)				(6,648)								6,648
Conversion and redemption of Omega OP Units to common stock						114,948		296		114,652								(114,948)
Omega OP Units distributions																		(21,294)		(21,294)
Noncontrolling interest - consolidated joint venture			$ 228	228														228		228
Comprehensive income:
Foreign currency translation	8,114			8,114		7,931										7,931		183		8,114
Cash flow hedges	(6,363)			(6,363)		(6,137)										(6,137)		(226)		(6,363)
Net income	351,959		$ (12)	351,947		341,123						341,123						10,824		351,947
Total comprehensive income	$ 353,710			$ 353,698																353,698
Balance , ending at Dec. 31, 2019		$ (41,889)				4,135,428		$ 22,663		$ 5,992,733		2,463,436		$ (4,303,546)		$ (39,858)		201,166		4,336,594
Increase (Decrease) In Stockholders' Equity [Roll Forward]
Cumulative effect of accounting change						$ (8,198)						$ (8,198)						$ (292)		$ (8,490)