Long-Term Debt - Finance Leases (Details) - USD ($) $ in Millions		6 Months Ended	12 Months Ended
	Dec. 31, 2019	Jun. 30, 2020	Dec. 31, 2019
Debt Disclosure [Abstract]
Imputed interest rate (percent)	3.30%
Weighted Average Estimated Life (in Years)			5 years
Finance lease liabilities		$ 8.3
Noncash investing and financing activity, unpaid portion, finance lease arrangements		$ 8.4