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, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Numerator for basic and diluted earnings per share:
Income from continuing operations	$ 156,930	$ 150,446	$ 465,114	$ 411,634
Discontinued operations	(19)	(118)	(95)	(755)
Gain (loss) on real estate dispositions	458,280	(144)	502,288	31,779
Net income	615,191	150,184	967,307	442,658	$ 651,490
Net income attributable to noncontrolling interests	1,233	732	3,391	1,064
Net income attributable to common stockholders	$ 613,958	$ 149,452	$ 963,916	$ 441,594
Denominator:
Denominator for basic earnings per share—weighted average shares (in shares)	355,929	350,274	355,110	341,610
Effect of dilutive securities:
Stock options (in shares)	624	847	528	594
Restricted stock awards (in shares)	318	193	236	168
OP unitholder interests (in shares)	2,462	2,872	2,491	2,980
Denominator for diluted earnings per share—adjusted weighted average shares (in shares)	359,333	354,186	358,365	345,352
Basic earnings per share:
Income from continuing operations (in usd per share)	$ 0.44	$ 0.43	$ 1.31	$ 1.20
Net income attributable to common stockholders (in usd per share)	1.72	0.43	2.71	1.29
Diluted earnings per share:
Income from continuing operations (in usd per share)	0.44	0.42	1.30	1.19
Net income attributable to common stockholders (in usd per share)	$ 1.71	$ 0.42	$ 2.69	$ 1.28