Contingent Liabilities (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
YP Acquisition
Loss Contingencies [Line Items]
Amount to be paid before allowance of tax credit	$ 8.0
Value of escrowed stock	25.2	$ 24.3
New York State Division of Taxation and Finance
Loss Contingencies [Line Items]
Sales and excise tax payable	2.8
IRS | Section 199 Tax Case
Loss Contingencies [Line Items]
Reserve in connection with disallowance	32.7	31.9
Amount to be paid before allowance of tax credit	8.0
IRS | Research and Development Tax Case
Loss Contingencies [Line Items]
Reserve in connection with disallowance	0.1	$ 0.2
Texas Comptroller
Loss Contingencies [Line Items]
Sales and excise tax payable	$ 2.6