CONSOLIDATED CONDENSED STATEMENTS OF CASH FLOWS (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Repayment of Sellers' Floor Plan Notes Payable Dealership Acquisitions	$ 0.0	$ 25.8
3.75% senior subordinated notes due 2020
Interest rate (as a percent)	3.75%
5.50% senior subordinated notes due 2026
Interest rate (as a percent)	5.50%