BUSINESS COMBINATIONS - Purchase Price Allocation (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018	Apr. 02, 2018	Dec. 31, 2017
Preliminary Recording of Assets Acquired and Liabilities Assumed
Goodwill		$ 955,881	$ 956,029		$ 184,932
ABILITY Network
Preliminary Recording of Assets Acquired and Liabilities Assumed
Cash and cash equivalents				$ 23,850
Accounts receivable				16,739
Income tax receivable				688
Prepaid expenses and other current assets				3,025
Property, equipment and capitalized software				3,095
Goodwill				770,949
Intangible assets				490,000
Other assets				1,252
Accounts payable and accrued expenses				(6,863)
Deferred revenue				(7,000)
Other current liabilities				(507)
Other liabilities				(5,291)
Deferred tax liabilities				(98,887)
Total consideration transferred				$ 1,191,050
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustments [Abstract]
Intangible assets	$ 23,000
Goodwill adjustment	1,800
Deferred tax liability adjustment	(5,000)
Income tax receivable adjustment	200
Shareholder payable adjustment	900
ABILITY Network | Customer Relationships
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustments [Abstract]
Deferred tax liability adjustment	$ 7,500