Segments Information - Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Segments Information
Revenue	$ 1,606,745	$ 1,474,347	$ 2,634,018	$ 2,539,116
Intersegment Eliminations
Segments Information
Revenue	(6,248)	(13,223)	(11,760)	(24,035)
Good Sam Services and Plans
Segments Information
Revenue	44,519	44,694	91,727	91,660
Good Sam Services and Plans | Intersegment Eliminations
Segments Information
Revenue	(173)	(297)	(1,657)	(1,629)
New vehicles
Segments Information
Revenue	898,175	778,870	1,395,492	1,308,447
New vehicles | Intersegment Eliminations
Segments Information
Revenue	(2,070)	(1,826)	(3,149)	(2,998)
Used vehicles
Segments Information
Revenue	274,910	245,749	481,575	425,757
Used vehicles | Intersegment Eliminations
Segments Information
Revenue	(789)	(782)	(1,357)	(1,379)
Products, service and other
Segments Information
Revenue	231,172	264,426	403,795	469,302
Products, service and other | Intersegment Eliminations
Segments Information
Revenue	(340)	(7,045)	(729)	(12,367)
Finance and insurance, net
Segments Information
Revenue	147,318	128,225	239,774	220,116
Finance and insurance, net | Intersegment Eliminations
Segments Information
Revenue	(2,876)	(3,273)	(4,868)	(5,662)
Good Sam Club
Segments Information
Revenue	10,651	12,383	21,655	23,834
Good Sam Services and Plans | Operating Segments
Segments Information
Revenue	44,692	44,991	93,384
Good Sam Services and Plans | Good Sam Services and Plans | Operating Segments
Segments Information
Revenue	44,692	44,991	93,384
Good Sam Services and Plans | Consumer Services and Plans | Operating Segments
Segments Information
Revenue				93,289
RV and Outdoor Retail
Segments Information
Revenue	1,562,226	1,429,653	2,542,291	2,447,456
RV and Outdoor Retail | Operating Segments
Segments Information
Revenue	1,568,301	1,442,579	2,552,394	2,469,862
RV and Outdoor Retail | New vehicles
Segments Information
Revenue	898,175	778,870	1,395,492	1,308,447
RV and Outdoor Retail | New vehicles | Operating Segments
Segments Information
Revenue	900,245	780,696	1,398,641	1,311,445
RV and Outdoor Retail | Used vehicles
Segments Information
Revenue	274,910	245,749	481,575	425,757
RV and Outdoor Retail | Used vehicles | Operating Segments
Segments Information
Revenue	275,699	246,531	482,932	427,136
RV and Outdoor Retail | Products, service and other
Segments Information
Revenue	231,172	264,426	403,795	469,302
RV and Outdoor Retail | Products, service and other | Operating Segments
Segments Information
Revenue	231,512	271,471	404,524	481,669
RV and Outdoor Retail | Finance and insurance, net
Segments Information
Revenue	147,318	128,225	239,774	220,116
RV and Outdoor Retail | Finance and insurance, net | Operating Segments
Segments Information
Revenue	150,194	131,498	244,642	225,778
RV and Outdoor Retail | Good Sam Club
Segments Information
Revenue	10,651	12,383	21,655	23,834
RV and Outdoor Retail | Good Sam Club | Operating Segments
Segments Information
Revenue	$ 10,651	$ 12,383	$ 21,655	$ 23,834