Income Taxes - Reconciliation of the Beginning and Ending Amounts of Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of year	$ 48,845	$ 44,088	$ 50,510
Additions based on tax positions related to current year	16,424	11,154	6,157
Reductions based on tax positions related to current year	0	0	0
Additions based on tax positions related to prior years	199	2,556	147
Reductions based on tax positions related to prior years	(8,198)	(5,461)	(8,201)
Reductions due to settlements with taxing authorities	(2,160)		(258)
Reductions due to statute of limitations lapse	(6,505)	(3,492)	(4,267)
Balance at end of year	$ 48,605	$ 48,845	$ 44,088

Unrecognized tax benefits increases decreases resulting from settlements with taxing authorities.

No definition available.

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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- Definition

Amount of unrecognized tax benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
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- Definition

Amount of decrease 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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-Publisher FASB
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- Definition

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

+ References

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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

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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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- Definition

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

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