Debt and Commitments (Details 2) $ in Thousands	12 Months Ended
Dec. 31, 2014 USD ($)
Debt Instrument [Line Items]
Interest expense on convertible notes	$ 1,777
Coupon [Member] \| Convertible Debt [Member] \| 3.375% Convertible Notes [Member]
Debt Instrument [Line Items]
Interest expense on convertible notes	1,046
Debt discount amortization [Member] \| Convertible Debt [Member] \| 3.375% Convertible Notes [Member]
Debt Instrument [Line Items]
Interest expense on convertible notes	$ 731

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

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