INCOME TAXES: (Details Textual) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Line Items]
Deferred Tax Assets, Valuation Allowance	$ 358,400,000	$ 322,500,000	$ 279,600,000
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	35.00%
Income Tax Examination, Penalties and Interest Expense	21,000
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	3,400,000
Domestic Tax Authority [Member]
Income Tax Disclosure [Line Items]
Operating Loss Carryforwards	862,500,000
Domestic Tax Authority [Member] | Minimum [Member]
Income Tax Disclosure [Line Items]
Open Tax Year	2010
Domestic Tax Authority [Member] | Maximum [Member]
Income Tax Disclosure [Line Items]
Open Tax Year	2014
State and Local Jurisdiction [Member]
Income Tax Disclosure [Line Items]
Operating Loss Carryforwards	914,100,000
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	$ 57,200,000