Segment Reporting (Disaggregation of Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation of Revenue [Line Items]
Net sales	$ 525,765	$ 629,068	$ 1,185,435	$ 1,221,240
OEM Segment
Disaggregation of Revenue [Line Items]
Net sales	367,812	553,368	900,169	1,085,148
Travel trailers and fifth-wheels
Disaggregation of Revenue [Line Items]
Net sales	212,518	343,051	519,626	659,922
Motorhomes
Disaggregation of Revenue [Line Items]
Net sales	24,713	41,357	62,800	86,357
Adjacent industries OEMs
Disaggregation of Revenue [Line Items]
Net sales	130,581	168,960	317,743	338,869
Aftermarket Segment
Disaggregation of Revenue [Line Items]
Net sales	157,953	75,700	285,266	136,092
Chassis, chassis parts and slide-out mechanisms | OEM Segment
Disaggregation of Revenue [Line Items]
Net sales	131,540	213,209	333,803	417,592
Windows and doors | OEM Segment
Disaggregation of Revenue [Line Items]
Net sales	109,696	156,064	265,727	307,983
Furniture and mattresses | OEM Segment
Disaggregation of Revenue [Line Items]
Net sales	57,662	93,562	144,842	184,919
Axles and suspension solutions | OEM Segment
Disaggregation of Revenue [Line Items]
Net sales	25,606	33,957	60,742	66,192
Other | OEM Segment
Disaggregation of Revenue [Line Items]
Net sales	43,308	56,576	95,055	108,462
U.S.
Disaggregation of Revenue [Line Items]
Net sales	481,707	597,592	1,080,522	1,156,148
U.S. | OEM Segment
Disaggregation of Revenue [Line Items]
Net sales	327,036	524,722	804,233	1,026,746
U.S. | Travel trailers and fifth-wheels
Disaggregation of Revenue [Line Items]
Net sales	204,977	340,025	508,659	653,392
U.S. | Motorhomes
Disaggregation of Revenue [Line Items]
Net sales	13,505	28,943	40,419	60,864
U.S. | Adjacent industries OEMs
Disaggregation of Revenue [Line Items]
Net sales	108,554	155,754	255,155	312,490
U.S. | Aftermarket Segment
Disaggregation of Revenue [Line Items]
Net sales	154,671	72,870	276,289	129,402
International
Disaggregation of Revenue [Line Items]
Net sales	44,058	31,476	104,913	65,092
International | OEM Segment
Disaggregation of Revenue [Line Items]
Net sales	40,776	28,646	95,936	58,402
International | Travel trailers and fifth-wheels
Disaggregation of Revenue [Line Items]
Net sales	7,541	3,026	10,967	6,530
International | Motorhomes
Disaggregation of Revenue [Line Items]
Net sales	11,208	12,414	22,381	25,493
International | Adjacent industries OEMs
Disaggregation of Revenue [Line Items]
Net sales	22,027	13,206	62,588	26,379
International | Aftermarket Segment
Disaggregation of Revenue [Line Items]
Net sales	$ 3,282	$ 2,830	$ 8,977	$ 6,690