Income Tax Matters - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income tax provision	$ 1.3	$ 7.3	$ 10.9	$ 17.1
Effective tax rate (percent)	(24.00%)	27.00%	33.00%	27.00%
Effective tax rate reconciliation, increase (decrease) to the valuation allowance for certain state net operating losses	$ 1.0		$ 1.3	$ 0.8
Effective tax rate reconciliation, increase (decrease) to the valuation allowance for certain state net operating losses (percent)	19.00%		4.00%	1.00%
Effective tax rate reconciliation, change in forecasted earnings	$ 1.9
Effective income tax rate reconciliation, change in forecasted earnings percent	37.00%
Effective income tax rate reconciliation, nondeductible expense, amount		$ 0.5	$ 0.8	$ 0.9
Effective income tax rate reconciliation, nondeductible expense, percent		2.00%	2.00%	2.00%
Effective tax rate reconciliation, unrecognized tax benefit amount		$ 0.2
Effective income tax rate reconciliation, unrecognized tax benefit percent		1.00%
Effective income tax rate reconciliation, tax expense (benefit), share-based payment arrangement, amount			$ (0.6)	$ (0.5)
Effective income tax rate reconciliation, tax expense (benefit), share-based payment arrangement, percent			2.00%	1.00%
Gross unrecognized tax benefits	$ 3.9		$ 3.9		$ 4.1
Gross unrecognized tax benefits that would impact effective tax rate	$ 0.4		$ 0.4		$ 0.9

Effective income tax rate reconciliation, unrecognized tax benefit percent.

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Effective tax rate reconciliation change in forecasted earnings percent.

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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 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 nondeductible expenses.

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