CONSOLIDATED STATEMENT OF CHANGES IN EQUITY (Unaudited) - 3 months ended Mar. 31, 2017 - USD ($) $ in Thousands	Common Stock Par Value	Additional Paid-in Capital	Cumulative Net Earnings	Cumulative Dividends Paid	Accumulated Other Comprehensive Income (Loss)	Total Stockholders' Equity	Noncontrolling Interest	Total
Balance (196,142 common shares & 8,862 OP Units) at Dec. 31, 2016	$ 19,614	$ 4,861,408	$ 1,738,937	$ (2,707,387)	$ (53,827)	$ 3,858,745	$ 353,241	$ 4,211,986
Increase (Decrease) In Stockholders' Equity [Roll Forward]
Stock-based compensation expense		3,744				3,744		3,744
Vesting/exercising of equity compensation plan, net of tax withholdings (103 shares)	10	(2,130)				(2,120)		(2,120)
Dividend reinvestment and stock purchase plan (239 shares at an average of $30.67 per share)	24	7,311				7,335		7,335
Grant of stock as payment of directors fees (2 shares at an average of $31.19 per share)		75				75		75
Deferred compensation directors		(16)				(16)		(16)
Equity Shelf Program (228 shares at $29.71 per share, net of issuance costs)	23	6,736				6,759		6,759
Common dividends declared ($0.62 per share)				(122,331)		(122,331)		(122,331)
Conversion of OP Units to common stock (47 shares at $32.30 per share)	5	1,509				1,514		1,514
Redemption of OP Units (48 units)							(1,570)	(1,570)
OP units distributions							(5,554)	(5,554)
Foreign currency translation					4,149	4,149	185	4,334
Cash flow hedges					1,200	1,200	54	1,254
Net income			104,440			104,440	4,672	109,112
Balance (196,761 shares & 8,814 OP Units) at Mar. 31, 2017	$ 19,676	$ 4,878,637	$ 1,843,377	$ (2,829,718)	$ (48,478)	$ 3,863,494	$ 351,028	$ 4,214,522