Reconciliation of Beginning and Ending Balances of Gross Unrecognized Tax Benefits (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reconciliation of Unrecognized Tax Benefits [Line Items]
Balance as of January 1,	$ 40,929us-gaap_UnrecognizedTaxBenefits	$ 26,317us-gaap_UnrecognizedTaxBenefits	$ 25,312us-gaap_UnrecognizedTaxBenefits
Additions based on tax positions related to the current year	4,041	4,320	3,855
Additions for tax positions of prior years	285	350	969
(Reductions) Additions for acquired uncertain tax benefits	(716)	10,268
Reductions for tax positions of prior years	(1,143)	(326)	(3,819)
Balance as of December 31,	$ 43,396us-gaap_UnrecognizedTaxBenefits	$ 40,929us-gaap_UnrecognizedTaxBenefits	$ 26,317us-gaap_UnrecognizedTaxBenefits

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Amount of increase or decrease in acquired unrecognized tax benefits resulting from acquisitions.

+ References

No definition available.

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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

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- Definition

Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

+ 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)(1)

-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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Amount of increase in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

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