PRO FORMA FINANCIAL INFORMATION - Schedule of Pro Forma Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Net income attributable to common stockholders, per:
Weighted-average number of common shares outstanding, basic (in shares)	112,149,638	65,312,288	81,150,846	65,285,591
Weighted-average number of common shares outstanding, diluted (in shares)	112,418,100	65,591,428	81,429,044	65,470,589
Series of Individually Immaterial Business Acquisitions [Member]
Business Acquisition [Line Items]
Revenues	$ 162,128	$ 158,245	$ 480,287	$ 491,049
Net income attributable to common stockholders	$ 37,823	$ 78,483	$ 209,674	$ 177,067
Net income attributable to common stockholders, per:
Basic common share (in dollars per share)	$ 0.24	$ 0.49	$ 1.31	$ 1.11
Diluted common share (in dollars per share)	$ 0.24	$ 0.49	$ 1.31	$ 1.11
Weighted-average number of common shares outstanding, basic (in shares)	160,189,442	159,347,649	159,685,873	159,320,952
Weighted-average number of common shares outstanding, diluted (in shares)	160,457,904	159,626,789	159,964,071	159,505,950