Income Taxes - Reconciliation of 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]
Gross unrecognized tax benefits at the beginning of the year	$ 12,523us-gaap_UnrecognizedTaxBenefits	$ 17,537us-gaap_UnrecognizedTaxBenefits	$ 9,026us-gaap_UnrecognizedTaxBenefits
Increases (reductions) related to prior year tax positions	(1,571)	(5,921)	8,602
Increases related to current year tax positions	1,377	2,044	1,255
Reductions as a result of a lapse of the statute of limitations	(3,624)	(1,137)	(1,346)
Gross unrecognized tax benefits at the end of the year	$ 8,705us-gaap_UnrecognizedTaxBenefits	$ 12,523us-gaap_UnrecognizedTaxBenefits	$ 17,537us-gaap_UnrecognizedTaxBenefits

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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

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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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- Definition

Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations.

+ 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)(4)

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

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- Definition

Unrecognized tax benefits increases decreases resulting from prior period tax positions.

+ References

No definition available.

+ Details

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