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RELATED PARTY TRANSACTIONS (NARRATIVE) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Related Party Transaction Line Items
Revenues	$ 364,936,000	$ 359,036,000	$ 1,090,038,000	$ 1,050,742,000
Airmax [Member]
Related Party Transaction Line Items
Purchases from Related Party			900,000	600,000
Accounts Payable Due from Related Party	142,000		142,000
Conversent [Member]
Related Party Transaction Line Items
Purchases from Related Party			45,000	55,000
CafeX [Member]
Related Party Transaction Line Items
Purchases from Related Party			44,000	60,000
Motif [Member]
Related Party Transaction Line Items
OperatingLeasesFutureMinimumPaymentsDue	$ 105,000		$ 105,000
Lease Expiration Date			Feb. 01, 2022
Welltok
Related Party Transaction Line Items
Revenues			$ 3,400,000	$ 3,300,000