ACQUISITIONS - Preliminary Purchase Price Allocation and Other Adjustments to Purchase Price Allocations (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Goodwill	$ 3,790,016	$ 3,758,177		$ 2,418,832
Series of Individually Immaterial Business Acquisitions [Member]
Business Acquisition [Line Items]
Fixed assets	3,345		$ (1,477)
Intangibles	8,436		19,791
Goodwill	25,519		41,190
Accounts receivable	1,715		4,217
Net other assets/ (liabilities)	133		59
Current liabilities	(201)		(4,650)
Net deferred tax liabilities	(1,050)		(3,377)
Total purchase price allocation	$ 37,897		$ 55,753