Schedule of pre-tax income.

No definition available.

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- Definition

Amount of tax benefit for recognition of expense of award under share-based payment arrangement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

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- Definition

Tax year being audited in the income tax examination, in CCYY format.

+ References

No definition available.

+ Details

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- Definition

Amount of increase (decrease) in unrecognized tax benefits attributable to uncertain tax positions taken in tax returns.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 15A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319

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Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Schedule Of Pre Tax Income [Line Items]
Excess tax benefits on share based payments	$ 5.9	$ 3.5	$ 17.9	$ 7.0
Additional provision for unrecognized tax benefits	$ 4.8
New York State [Member] \| Earliest Tax Year [Member]
Schedule Of Pre Tax Income [Line Items]
Income tax year under examination			2010
New York State [Member] \| Latest Tax Year [Member]
Schedule Of Pre Tax Income [Line Items]
Income tax year under examination			2017
New York City [Member] \| Earliest Tax Year [Member]
Schedule Of Pre Tax Income [Line Items]
Income tax year under examination			2016
New York City [Member] \| Latest Tax Year [Member]
Schedule Of Pre Tax Income [Line Items]
Income tax year under examination			2018