Consolidated Statement Of Changes In Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Preferred Stock [Member]	Additional Paid-in Capital [Member]	Treasury shares [Member]	Accumulated other comprehensive income (loss) [Member]	Distributions in excess of net income [Member]	Series C Preferred Shares [Member]	Series C Preferred Shares [Member] Distributions in excess of net income [Member]	Series E Preferred Shares [Member]	Series E Preferred Shares [Member] Distributions in excess of net income [Member]	Series G Preferred Stock [Member]	Series G Preferred Stock [Member] Distributions in excess of net income [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total equity	$ 2,865,023	$ 772	$ 148	$ 3,504,494	$ (130,728)	$ 12,085	$ (521,748)
Balance (in shares) at Dec. 31, 2018		77,226,443	14,841,431
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock Issued During Period, Shares, Other		1,156
Stock Issued During Period, Value, Other	0
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures		197,755
Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures	4,430	$ 2		4,831	(403)
Treasury Stock, Retired, Cost Method, Amount	(9,499)				(9,499)
Employee Service Share Based Compensation Restricted Stock Units And Restricted Shares Unrecognized Compensation Cost On Nonvested Awards	3,177			3,177
share based compensation included in severance expense	103			103
Foreign currency translation adjustment	3,810					3,810
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	(7,498)					(7,498)
Net income	65,349						65,349
Issuances of common shares (in shares)		1,064,600
Issuances of common shares	78,993	$ 11		78,982
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period		111,815
Stock Issued During Period, Value, Stock Options Exercised	732	$ (1)		(5,543)	(6,276)
Dividends to common and preferred shareholders	(84,343)						(84,343)	$ (1,939)	$ (1,939)	$ (1,939)	$ (1,939)	$ (2,156)	$ (2,156)
Balance (in shares) at Mar. 31, 2019		78,601,769	14,841,431
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total equity	2,912,779	$ 786	$ 148	3,597,130	(146,906)	8,397	(546,776)
Total equity	3,005,805	$ 816	$ 148	3,834,858	(147,435)	7,275	(689,857)
Balance (in shares) at Dec. 31, 2019		81,588,489	14,841,431
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures		211,549
Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures	6,133	$ 2		6,221	(90)
Treasury Stock, Retired, Cost Method, Amount	(6,769)				(6,769)
Employee Service Share Based Compensation Restricted Stock Units And Restricted Shares Unrecognized Compensation Cost On Nonvested Awards	3,509			3,509
Foreign currency translation adjustment	(16,495)					(16,495)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	3,931					3,931
Net income	37,118						37,118
Issuances of common shares (in shares)		10,368
Issuances of common shares	$ 442	$ 0		442
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	1,410	1,410
Stock Issued During Period, Value, Stock Options Exercised	$ 0	$ 0		(63)	63
Dividends to common and preferred shareholders	(88,996)						(88,996)	$ (1,939)	$ (1,939)	$ (1,939)	$ (1,939)	$ (2,156)	$ (2,156)
Balance (in shares) at Mar. 31, 2020		81,811,816	14,841,431
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total equity	2,936,481	$ 818	$ 148	$ 3,845,093	$ (154,357)	$ (5,289)	(749,932)
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets	$ (2,163)						$ (2,163)