Consolidated Statements of Stockholders' Equity (Parenthetical) $ in Thousands	12 Months Ended
Dec. 31, 2013 USD ($)
Statement of Stockholders' Equity [Abstract]
Convertible senior notes, issuance costs	$ 714
Tax effect on convertible senior notes	$ 7,785

Adjustment to additional paid in capital resulting from the recognition of convertible debt instruments as two separate components - a debt component and an equity component. This bifurcation may result in a basis difference associated with the liability component that represents a temporary difference for purposes of applying accounting for income taxes. The initial recognition of deferred taxes for the tax effect of that temporary difference is as an adjustment to additional paid in capital.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 25
-Paragraph 22
-URI http://asc.fasb.org/extlink&oid=51819886&loc=SL6014347-161799

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