Tax Receivable Agreement (Details) $ in Millions	9 Months Ended
	Sep. 30, 2018 USD ($)
Tax Receivable Agreement
Payment on applicable cash tax savings (as a percent)	85.00%
Minimum first payment due after filing of companys tax return	95 days
Maximum first payment due after filing of companys tax return	125 days
Payments to the Continuing LLC Owners	$ 49.9
Deferred tax assets related to exchange of units	42.4
Minimum tax receivable agreement obligation over the agreed period	0.0
Maximum tax receivable agreement obligation over the agreed period	$ 3.6
Period over which the obligations are to be settled	15 years
Deferred tax asset recorded in connection with a stock offering	$ 49.9
Amount of payment liability pursuant to tax receivable agreements	$ 42.4