DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES: (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014	Sep. 27, 2014
Derivative contracts
Assets	$ 49	$ 23	$ 20
Liabilities	(3,958)	(2,699)	(1,635)
Derivatives designated as hedging instruments:
Derivative contracts
Assets	49	23	20
Liabilities	(3,958)	(2,699)	(1,635)
Derivatives designated as hedging instruments: | Foreign currency forward contracts
Derivative contracts
Notional Amounts	22,500	27,603	33,291
Assets			20
Liabilities	(2,977)	(1,939)	(1,258)
Derivatives designated as hedging instruments: | Commodity futures contracts
Derivative contracts
Notional Amounts	10,263	5,422	3,352
Assets	49	23
Liabilities	$ (981)	$ (760)	$ (377)