Acquisitions - General Information (Details) - Assets Or Stock Of Multiple Dealership Locations Acquired - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016
Acquisitions
Real properties purchased	$ 17.1	$ 15.3
Real properties sold in sale-leaseback transactions	$ 6.0	$ 15.9

Real properties sold in sale-leaseback transactions during the period.

No definition available.

Name:	cwh_SaleLeasebackTransactionRealPropertiesSold
Namespace Prefix:	cwh_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration