Commitments and Contingencies (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Dec. 31, 2019	Dec. 31, 2018
Other Commitments [Line Items]
Remaining principal balance	$ 26.8	$ 42.4
Payment to ESCO for debt repayment and repurchase of shares	6.2
Repurchase of Class A Common Stock	3.1
Class A Common Stock
Other Commitments [Line Items]
Repurchase of Class A Common Stock	2.4
ESCO Notes Payable
Other Commitments [Line Items]
Remaining principal balance	0.0	$ 5.8	$ 5.8
Payment for retirement of debt	$ 3.8