STOCKHOLDERS' EQUITY: (Details 4) $ / shares in Units, $ in Millions	6 Months Ended			12 Months Ended
	Jun. 30, 2015 USD ($) MXN / shares	Jun. 30, 2015 USD ($) $ / shares shares	Jun. 30, 2014 USD ($) $ / shares shares	Dec. 31, 2010 $ / shares	Dec. 31, 2010 MXN / shares
Stock award activity, Shares
Granted (in shares)		13,200	12,000
Employee Stock Purchase 2007 Plan
Information related to compensation cost
Stock based compensation expense | $			$ 1.1
Unrecognized compensation expense | $			$ 1.0
Stock award activity, Shares
Outstanding shares at the beginning of the period		4,298,612	4,449,599
Exercised (in shares)		(4,128,970)	(58,663)
Outstanding shares at the end of the period		169,642	4,390,936
Unit Weighted Average Grant Date Fair Value
Outstanding shares at the beginning of the period (in dollars per share) | $ / shares		$ 1.16	$ 1.16
Exercised (in dollars per share) | $ / shares		1.16	1.16
Outstanding shares at the end of the period (in dollars per share) | $ / shares		$ 1.16	$ 1.16
Employee Stock Purchase 2010 Plan
Information related to compensation cost
Stock based compensation expense | $		$ 0.2	$ 0.1
Unrecognized compensation expense | $	$ 1.9	$ 1.9	$ 2.4
Period over which unrecognized compensation expense expected to be recognized		3 years 6 months
Stock award activity, Shares
Outstanding shares at the beginning of the period		2,287,891	3,012,464
Exercised (in shares)		(20,273)	(669,157)
Outstanding shares at the end of the period		2,267,618	2,343,307
Unit Weighted Average Grant Date Fair Value
Outstanding shares at the beginning of the period (in dollars per share) | $ / shares		$ 2.05	$ 2.05
Exercised (in dollars per share) | $ / shares		2.05	2.05
Outstanding shares at the end of the period (in dollars per share) | $ / shares		$ 2.05	$ 2.05
Purchase price for initial subscription (in dollars per share) | (per share)				$ 2.05	MXN 26.51
Employee Stock Purchase 2015 Plan
Information related to compensation cost
Stock based compensation expense | $		$ 0.0
Unrecognized compensation expense | $	$ 4.8	$ 4.8
Stock award activity, Shares
Granted (in shares)		2,652,886
Outstanding shares at the end of the period		2,652,886
Unit Weighted Average Grant Date Fair Value
Granted (in dollars per share) | $ / shares		$ 2.63
Outstanding shares at the end of the period (in dollars per share) | $ / shares		2.63
Purchase price for initial subscription (in dollars per share) | (per share)	$ 38.44	$ 2.63