Employee Benefit Plan (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014
Employee Benefit Plan
Employer contributions	$ 0

Amount of discretionary contributions made by an employer to a defined contribution plan.

No definition available.

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