SUPPLEMENTAL BALANCE SHEET AND CASH FLOW INFORMATION (other non-current assets) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Other non-current assets
Loans and notes receivable from Safeguard distributors		$ 66,872	$ 78,693
Postretirement benefit plan asset (Note 14)		56,743	41,259
Prepaid product discounts		51,145	54,642	$ 63,895	$ 65,792
Deferred sales commissions	[1]	9,682	6,482
Other		13,428	15,032
Other non-current assets		197,870	196,108
Amortization of deferred sales commissions		$ 3,108	$ 2,722

[1] Amortization of deferred sales commission was $3,108 for 2019 and $2,722 for 2018.