Income Taxes - Schedule of Reconciliation of Statutory U.S. Federal Income Tax Rate to Effective Income Tax Rate for Continuing Operations (Detail)	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Effective Income Tax Rate Continuing Operations Tax Rate Reconciliation [Abstract]
Statutory U.S. federal income tax rate	21.00%	21.00%	35.00%
State and local income taxes	2.70%	3.10%	2.30%
Stock-based compensation	(1.30%)	(1.40%)	3.20%
Valuation allowance			0.30%
Legal settlement		1.40%
State audit settlement	(0.50%)	0.10%	(4.60%)
Federal income tax rate change			145.30%
Tax credits	(0.10%)	(0.20%)	(0.70%)
Other	2.30%	1.00%	4.40%
Effective income tax rate	24.10%	25.00%	185.20%

Effective income tax rate reconciliation nondeductible expense legal settlement.

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

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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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Percentage of difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying domestic federal statutory income tax rate to pretax income (loss) from continuing operation, attributable to nondeductible expense for share-based payment arrangement.

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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 tax credits. Including, but not limited to, research credit, foreign tax credit, investment tax credit, and other tax credits.

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