Fair value input discount rate.

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Fair value inputs long-term growth rate.

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Fair value measurements valuation process multiple used.

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Impairment of goodwill and idefinite lived intangibles.

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Percentage weighted income approach to determine fair value of company's reporting units.

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Percentage weighted market approach to determine fair value of company's reporting units.

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The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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Amount of amortization for assets, excluding financial assets and goodwill, lacking physical substance with finite life expected to be recognized in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of amortization for assets, excluding financial assets and goodwill, lacking physical substance with finite life expected to be recognized in remainder of current fiscal year.

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Amount of amortization for assets, excluding financial assets and goodwill, lacking physical substance with finite life expected to be recognized in fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of amortization for assets, excluding financial assets and goodwill, lacking physical substance with finite life expected to be recognized in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of amortization for assets, excluding financial assets and goodwill, lacking physical substance with finite life expected to be recognized in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of impairment loss resulting from write-down of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit to fair value.

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Amount of fair value of reporting unit in excess of carrying amount.

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Goodwill and Other Intangible Assets - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Non-cash impairment charge recognized				$ 13,772		$ 13,772
Impairment charges			$ 193,600				$ 102,200
Weighted income approach to determine the fair value of the company's reporting units	75.00%			75.00%
Weighted market approach to determine the fair value of the company's reporting units	25.00%			25.00%
Amortization of intangible assets	$ 6,500	$ 6,500		$ 19,900	$ 18,800
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2021	25,800			25,800
2022	22,900			22,900
2023	20,900			20,900
2024	20,900			20,900
2025	$ 10,300			$ 10,300
Market Approach Valuation Technique [Member]
Finite-Lived Intangible Assets [Line Items]
Fair value measurements valuation process multiple used			4.9X EBITDA				5.7X EBITDA
Measurement Input, Discount Rate [Member]
Finite-Lived Intangible Assets [Line Items]
Discount rate			12.00%				10.00%
Measurement Input, Long-term Revenue Growth Rate [Member]
Finite-Lived Intangible Assets [Line Items]
Long-term growth rate			1.50%				2.00%
Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Non-cash impairment charge recognized			$ 11,000
European Operations [Member]
Finite-Lived Intangible Assets [Line Items]
Amount of fair value in excess of carrying value			$ 182,600