Income Taxes - Unrecognized Tax Benefits (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefits at beginning of period	$ 415us-gaap_UnrecognizedTaxBenefits	$ 344us-gaap_UnrecognizedTaxBenefits	$ 1,192us-gaap_UnrecognizedTaxBenefits
Gross increases to current period tax positions	128	161	0
Gross increases (decreases) to prior period tax positions	37	(90)	(848)
Unrecognized tax benefits at end of period	$ 580us-gaap_UnrecognizedTaxBenefits	$ 415us-gaap_UnrecognizedTaxBenefits	$ 344us-gaap_UnrecognizedTaxBenefits

Unrecognized Tax Benefits, Increase (Decrease) Resulting from Prior Period Tax Positions

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- Details

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- Definition

Amount of unrecognized tax benefits pertaining to uncertain tax positions taken in tax returns.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Unrecognized Tax Benefit

-URI http://asc.fasb.org/extlink&oid=6527854

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 15A

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6907707&loc=SL6600010-109319

+ Details

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- Definition

Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 15A

-Subparagraph (a)(2)

-URI http://asc.fasb.org/extlink&oid=6907707&loc=SL6600010-109319

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