Income taxes.

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- Definition

Amount of deferred income tax expense (benefit) pertaining to income (loss) from continuing operations.

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- Definition

Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount recognized for uncertainty in income taxes classified as noncurrent.

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- Definition

Tax year that remains open to examination under enacted tax laws, in YYYY format.

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Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Income Taxes [Line Items]
Liability for uncertain tax positions	$ 100		$ 100		$ 100
Deferred income taxes on undistributed earnings			0	$ 13
Income tax expense	$ 63	$ 206	$ 813	$ 1,549
Effective income tax rate	5.60%	468.20%	62.70%	19.40%
Foreign Subsidiaries [Member]
Income Taxes [Line Items]
Deferred income taxes on undistributed earnings			$ 1,200		$ 900
Federal Authorities [Member]
Income Taxes [Line Items]
Open tax years			2017
State and Foreign Authorities [Member]
Income Taxes [Line Items]
Open tax years			2015