Derivative Financial Instruments (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Sep. 30, 2019	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Agreement term		5 years
Aggregate notional amount		$ 300,000,000
Floor plan notes payable: non-trade	$ 1,594,500,000	$ 1,700,000,000	$ 1,594,500,000	$ 1,733,300,000
Fair value of derivative instruments	2,600,000		2,600,000
Amount reclassified from AOCI	$ 0		$ 0