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Income Taxes - Reconciliation of Beginning and Ending Amount of Gross Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Balance at beginning of year	$ 32,684	$ 27,345	$ 25,465
Increases/(decreases) for prior years	9,324	934	640
Increases for the current year	3,219	6,091	4,340
Reductions related to expiration of statutes of limitations and audit settlements	(1,734)	(1,686)	(3,100)
Balance at end of year	$ 43,493	$ 32,684	$ 27,345

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Unrecognized tax benefits increase decrease resulting from prior period tax positions.

+ References

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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
-Section 45
-Paragraph 10B
-URI http://asc.fasb.org/extlink&oid=116821951&loc=SL37586934-109318

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 15A
-Subparagraph (a)
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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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-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 15A
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Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations.

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