INVESTMENTS: (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012
Amortized Cost Basis	$ 3,300	$ 1,597
Gross Unrealized Losses	(31)	(11)
Gross Unrealized Gains	11	108
Fair Value	3,280	1,694
Corporate Debt Securities [Member]
Amortized Cost Basis	1,298	85
Gross Unrealized Losses	(7)	0
Gross Unrealized Gains	9	107
Fair Value	1,300	192
Mutual Funds [Member]
Amortized Cost Basis	2,002	1,512
Gross Unrealized Losses	(24)	(11)
Gross Unrealized Gains	2	1
Fair Value	$ 1,980	$ 1,502