Income Taxes - Summary of 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, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefits, beginning balance	$ 7,765us-gaap_UnrecognizedTaxBenefits	$ 9,051us-gaap_UnrecognizedTaxBenefits	$ 8,567us-gaap_UnrecognizedTaxBenefits
(Decreases) increases related to prior year tax positions	(68)	773	372
Increases related to current year tax positions	642	1,019	366
Decreases due to settlements	(42)	0	0
Expiration of the statute of limitations for the assessment of taxes	(1,232)	(3,078)	(254)
Unrecognized tax benefits, ending balance	$ 7,065us-gaap_UnrecognizedTaxBenefits	$ 7,765us-gaap_UnrecognizedTaxBenefits	$ 9,051us-gaap_UnrecognizedTaxBenefits

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

+ References

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-Publisher FASB

-Name Accounting Standards Codification

-Glossary Unrecognized Tax Benefit

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Amount of decrease in unrecognized tax benefits resulting from settlements with taxing authorities.

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

+ References

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

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