NEW ACCOUNTING STANDARDS (NARRATIVE) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018	Jan. 01, 2018
Retained earnings	$ 773,218		$ 725,551
Revenue, Remaining Performance Obligation, Optional Exemption, Performance Obligation [true false]	true
Revenue, Practical Expedient, Financing Component [true false]	true
Operating Lease, Right-of-Use Asset	$ 150,808	$ 129,894
Operating Lease, Liability		148,300
Lease, Practical Expedients, Package [true false]	true
Lease, Practical Expedient, Use of Hindsight [true false]	false
Lease, Practical Expedient, Lessor Single Lease Component [true false]	true
Deferred revenue - current	$ 39,447		$ 44,926
ASU 2016-02
Retained earnings		$ 800		$ 10,000