RESTRUCTURING AND INTEGRATION EXPENSE (restructuring and integration accruals) (Details) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019
Restructuring and integration accruals [Line Items]
Balance, beginning of year					$ 3,461					$ 3,461
Charges		$ 23,356	$ 27,674	$ 17,497	6,283	$ 7,406	$ 5,104	$ 6,371	$ 2,322	74,810	$ 21,203	$ 9,130
Balance, end of year						3,461					3,461
Employee severance [Member]
Restructuring and integration accruals [Line Items]
Balance, beginning of year					3,179				4,376	3,179	4,376	4,181
Charges										11,516	7,672	7,843
Reversals										(651)	(1,898)	(667)
Payments										(10,585)	(6,971)	(6,981)
Balance, end of year		3,459				3,179				3,459	3,179	4,376
Operating lease obligations [Member]
Restructuring and integration accruals [Line Items]
Balance, beginning of year					282				4	282	4	0
Charges										0	597	23
Reversals										0	(71)	0
Payments										0	(248)	(19)
Balance, end of year		0				282				0	282	4
Operating lease obligations [Member] | Accounting Standards Update No. 2016-02 [Member]
Restructuring and integration accruals [Line Items]
Adoption of ASU No. 2016-02	[1]												$ (282)
Employee severance and operating lease obligations [Member]
Restructuring and integration accruals [Line Items]
Balance, beginning of year					$ 3,461				$ 4,380	3,461	4,380	4,181
Charges										11,516	8,269	7,866
Reversals										(651)	(1,969)	(667)
Payments										(10,585)	(7,219)	(7,000)
Balance, end of year		$ 3,459				$ 3,461				$ 3,459	$ 3,461	$ 4,380

[1] Upon adoption of ASU No. 2016-02, Leasing, and related amendments on January 1, 2019 (Note 2), our operating lease obligation accrual was reversed and the related operating lease asset was analyzed for impairment in accordance with the new guidance.