Income Taxes - Reconciliation of the Beginning and Ending Uncertain Tax Positions (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Gross unrecognized tax benefits, Beginning balance	$ 2,763us-gaap_UnrecognizedTaxBenefits	$ 2,678us-gaap_UnrecognizedTaxBenefits	$ 2,526us-gaap_UnrecognizedTaxBenefits
Increases in tax positions for prior years	43		152
Decreases in tax positions for prior years	0	0	0
Increases in tax positions for current year		132
Decreases in tax positions for current year	(210)
Settlements	0	0	0
Lapse in statute of limitations	(2,429)	(47)
Gross unrecognized tax benefits, Ending balance	$ 167us-gaap_UnrecognizedTaxBenefits	$ 2,763us-gaap_UnrecognizedTaxBenefits	$ 2,678us-gaap_UnrecognizedTaxBenefits

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

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-Publisher FASB

-Name Accounting Standards Codification

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

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

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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.

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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 increase in unrecognized tax benefits resulting from settlements with taxing authorities.

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

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