Income Taxes - Classification of Net Deferred Income Tax Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Balance Sheet Classification of Deferred Income Tax Assets and Liabilities [Line Items]
Net deferred income tax assets	$ 11,790	$ 11,406
Other noncurrent assets
Balance Sheet Classification of Deferred Income Tax Assets and Liabilities [Line Items]
Net deferred income tax assets	72,682	67,900
Other noncurrent liabilities
Balance Sheet Classification of Deferred Income Tax Assets and Liabilities [Line Items]
Net deferred income tax (liabilities)	$ (60,892)	$ (56,494)

Balance Sheet Classification of Deferred Income Tax Assets and Liabilities [Line Items]

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Amount, after allocation of valuation allowances and deferred tax liability, of deferred tax asset attributable to deductible differences and carryforwards, with jurisdictional netting.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 45
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=120406818&loc=d3e31931-109318

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=120406818&loc=d3e31917-109318

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Amount, after deferred tax asset, of deferred tax liability attributable to taxable differences with jurisdictional netting.

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Amount, after allocation of valuation allowances and deferred tax liability, of deferred tax asset attributable to deductible differences and carryforwards, without jurisdictional netting.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32537-109319

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