CONSOLIDATED STATEMENTS OF OPERATIONS (Paranthetical) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014
CONSOLIDATED STATEMENTS OF OPERATIONS
Interest and investment income/ (expense), net (includes interest expense of $2,500 on Senior Convertible Debentures for year 2014), interest expense	$ 2,500us-gaap_InterestExpenseDebt

Amount of the cost of borrowed funds accounted for as interest expense for debt.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.8)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 8

-Article 5

Name:	us-gaap_InterestExpenseDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration