Income Taxes - Statutory rate (Details)		12 Months Ended
Jan. 01, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Schedule of reconciliation between statutory tax rate and effective tax rate
Statutory federal rate	21.00%	21.00%	21.00%	21.00%
State income taxes, net of federal benefits		5.60%	4.60%	(1.40%)
Termination of deferred compensation arrangements		0.00%	9.20%	0.00%
Transaction costs		0.60%	0.00%	(6.20%)
Excess tax benefit on share-based compensation		(2.00%)	(2.60%)	15.50%
Impact of foreign operations		(1.20%)	0.00%	0.00%
Impairment of intangible assets		0.00%	0.00%	(15.30%)
Other		0.30%	2.20%	4.50%
Effective tax rate		24.30%	34.40%	18.10%

Effective Income Tax Rate Reconciliation Deferred Termination Compensation Arrangements

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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 transaction costs.

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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 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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