Income Taxes - Reconciliation (Details)	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of the statutory federal income tax rate to effective income tax rate
Statutory federal income tax rate	21.00%	21.00%	21.00%
State income taxes, net of federal income tax benefit	(10.80%)	(1.60%)	(1.50%)
Goodwill impairment	(71.00%)	(28.60%)	(36.60%)
Change in liability for unrecognized tax position	(0.60%)	(0.20%)	1.30%
Legislative changes to GILTI	1.80%	0.00%	0.00%
Nondeductible executive stock compensation	(1.60%)	(0.10%)	0.00%
Change in valuation allowance	2.60%	0.00%	0.00%
Tax reform	0.00%	0.00%	(5.90%)
Net foreign income taxes	(0.60%)	(0.50%)	1.80%
Research and development credits	1.60%	0.10%	0.90%
Tax benefit of net operating loss carryback	0.00%	0.00%	9.10%
Other, net	0.10%	(0.70%)	(1.00%)
Effective income tax rate	(57.50%)	(10.60%)	(10.90%)

Effective Income Tax Rate Reconciliation, Legislative Changes To GILTI, Percent

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Effective Income Tax Rate Reconciliation, Nondeductible Expense, Executive Compensation, Percent

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Effective Income Tax Rate Reconciliation, Tax Benefit of Net Operating Loss Carryback

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

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to changes in the valuation allowance for deferred tax assets.

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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section S99
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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Topic 740
-SubTopic 10
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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations applicable to statutory income tax expense (benefit) outside of the country of domicile.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations applicable to state and local income tax expense (benefit), net of federal tax expense (benefit).

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to income tax contingencies. Includes, but not limited to, domestic tax contingency, foreign tax contingency, state and local tax contingency, and other contingencies.

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