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

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

Name:	us-gaap_EffectiveIncomeTaxRateContinuingOperations
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Income Taxes - Narrative (Detail)	3 Months Ended		9 Months Ended		12 Months Ended
Income Taxes - Narrative (Detail)	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2020
Income Tax Contingency [Line Items]
Effective income tax benefit rate	0.00%	(0.80%)	(0.00%)	(1.00%)
Scenario, Forecast
Income Tax Contingency [Line Items]
Effective income tax benefit rate					(0.10%)