EARNINGS PER COMMON SHARE (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Numerator for basic and diluted earnings per share:
Income from continuing operations	$ 152,272	$ 137,849	$ 308,184	$ 261,188
Discontinued operations	(23)	(148)	(76)	(637)
Gain on real estate dispositions	719	5,739	44,008	31,923
Net income	152,968	143,440	352,116	292,474	$ 651,490
Net income attributable to noncontrolling interests	1,137	278	2,158	332
Net income attributable to common stockholders	$ 151,831	$ 143,162	$ 349,958	$ 292,142
Denominator:
Denominator for basic earnings per share—weighted average shares (in shares)	355,024	338,901	354,719	337,230
Effect of dilutive securities:
Stock options (in shares)	596	630	501	475
Restricted stock awards (in shares)	225	154	193	153
OP units (in shares)	2,466	2,886	2,506	2,993
Denominator for diluted earnings per share—adjusted weighted average shares (in shares)	358,311	342,571	357,919	340,851
Basic earnings per share:
Income from continuing operations (in usd per share)	$ 0.43	$ 0.41	$ 0.87	$ 0.77
Net income attributable to common stockholders (in usd per share)	0.43	0.42	0.99	0.87
Diluted earnings per share:
Income from continuing operations (in usd per share)	0.42	0.40	0.86	0.77
Net income attributable to common stockholders (in usd per share)	$ 0.42	$ 0.42	$ 0.98	$ 0.86