EARNINGS PER COMMON SHARE (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Numerator for basic and diluted earnings per share:
Income from continuing operations	$ 103,263	$ 156,930	$ 316,796	$ 465,114
Discontinued operations	0	(19)	(10)	(95)
Gain on real estate dispositions	18	458,280	35,893	502,288
Net income	103,281	615,191	352,679	967,307	$ 1,361,112
Net income attributable to noncontrolling interests	1,309	1,233	5,485	3,391
Net income attributable to common stockholders	$ 101,972	$ 613,958	$ 347,194	$ 963,916
Denominator:
Denominator for basic earnings per share—weighted average shares (in shares)	356,318	355,929	356,224	355,110
Effect of dilutive securities:
Stock options (in shares)	227	624	152	528
Restricted stock awards (in shares)	396	318	271	236
OP Unitholder Interests (in shares)	2,414	2,462	2,421	2,491
Denominator for diluted earnings per share—adjusted weighted average shares (in shares)	359,355	359,333	359,068	358,365
Basic earnings per share:
Income from continuing operations (in usd per share)	$ 0.29	$ 0.44	$ 0.89	$ 1.31
Net income attributable to common stockholders (in usd per share)	0.29	1.72	0.97	2.71
Diluted earnings per share:
Income from continuing operations (in usd per share)	0.29	0.44	0.88	1.30
Net income attributable to common stockholders (in usd per share)	$ 0.28	$ 1.71	$ 0.97	$ 2.69