FAIR VALUE (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Oct. 31, 2019	May 31, 2019
Liabilities
Fair value of long-term obligations	$ 1,000,000	$ 1,100,000
Gateway Analytical
Liabilities
Fair value of contingent consideration arrangement	3,000	3,000		$ 3,000
Noble
Liabilities
Fair value of contingent consideration arrangement	2,900	2,900	$ 2,900
Assets and liabilities measured at fair value on recurring basis
Assets
Foreign exchange contracts, assets	2,061	206
Cross currency swap contract, asset	6,769	2,552
Total assets at fair value	8,830	2,758
Liabilities
Foreign exchange contracts, liabilities	505	401
Fair value of contingent consideration arrangement	5,930	5,930
Total liabilities at fair value	6,435	6,331
Assets and liabilities measured at fair value on recurring basis | Level 2
Assets
Foreign exchange contracts, assets	2,061	206
Cross currency swap contract, asset	6,769	2,552
Total assets at fair value	8,830	2,758
Liabilities
Foreign exchange contracts, liabilities	505	401
Total liabilities at fair value	505	401
Assets and liabilities measured at fair value on recurring basis | Level 3
Liabilities
Fair value of contingent consideration arrangement	5,930	5,930
Total liabilities at fair value	$ 5,930	$ 5,930