PRO FORMA FINANCIAL INFORMATION - Schedule of Pro Forma Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Net income attributable to common stockholders, per:
Weighted-average number of common shares outstanding, basic (in shares)	65,303,057	59,323,799	65,274,845	59,254,895
Weighted-average number of common shares outstanding, diluted (in shares)	65,503,383	59,543,781	65,454,337	59,510,164
Series of Individually Immaterial Business Acquisitions [Member]
Business Acquisition [Line Items]
Revenues		$ 63,015		$ 125,752
Depreciation and amortization		16,583		33,191
Net income attributable to common stockholders		$ 23,889		$ 45,394
Net income attributable to common stockholders, per:
Basic common share (in dollars per share)		$ 0.40		$ 0.77
Diluted common share (in dollars per share)		$ 0.40		$ 0.76
Weighted-average number of common shares outstanding, basic (in shares)		59,323,799		59,254,895
Weighted-average number of common shares outstanding, diluted (in shares)		59,543,781		59,510,164