Taxes on Income - Roll-Forward of Total Amounts of Company's Unrecognized Tax Benefits (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Balance at beginning of year	$ 19,633us-gaap_UnrecognizedTaxBenefits	$ 19,016us-gaap_UnrecognizedTaxBenefits	$ 18,301us-gaap_UnrecognizedTaxBenefits
Increases in unrecognized tax benefits as a result of tax positions taken during the year	1,412	2,376	1,821
Increase (decrease) in unrecognized tax benefits as a result of tax positions taken during a prior year		(869)	(121)
Decreases in unrecognized tax benefits as a result of statute of limitations expirations and tax audits	(2,358)	(890)	(985)
Balance at end of year	$ 18,687us-gaap_UnrecognizedTaxBenefits	$ 19,633us-gaap_UnrecognizedTaxBenefits	$ 19,016us-gaap_UnrecognizedTaxBenefits

Unrecognized Tax Benefits Increase Decrease Resulting From Prior Period Tax Positions

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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 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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