OTHER INCOME (LOSS): (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Other Income and Expenses [Abstract]
Effective income tax rate reconciliation, percent	1.00%	5.00%	2227.80%	9.90%
Other Nonoperating Income (Expense) [Abstract]
Interest income and gains (losses) on sale of investments, net	$ 674	$ 817	$ 744	$ 1,480
Impairment loss on equity investment in a private company	0	0	0	(3,189)
Foreign exchange gain (loss)	(359)	95	(368)	152
Other income (loss)	$ 315	$ 912	$ 376	$ (1,557)