Major Product Categories and Percentage of Consolidated Net Sales (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Product Information [Line Items]
Net external sales	$ 413,126	$ 362,408	$ 737,355	$ 640,090
Percentage of consolidated net sales	100.00%	100.00%	100.00%	100.00%
Commercial Trailer Products
Product Information [Line Items]
Net external sales	244,060	263,350	428,148	496,910
Diversified Products
Product Information [Line Items]
Net external sales	121,360	61,054	220,947	80,056
Retail
Product Information [Line Items]
Net external sales	47,706	38,004	88,260	63,124
New Trailers
Product Information [Line Items]
Net external sales	306,944	293,063	542,410	528,253
Percentage of consolidated net sales	74.30%	80.90%	73.60%	82.50%
New Trailers | Commercial Trailer Products
Product Information [Line Items]
Net external sales	232,848	255,543	407,850	480,842
New Trailers | Diversified Products
Product Information [Line Items]
Net external sales	51,232	21,007	94,753	21,007
New Trailers | Retail
Product Information [Line Items]
Net external sales	22,864	16,513	39,807	26,404
Used Trailers
Product Information [Line Items]
Net external sales	10,593	9,412	19,240	16,997
Percentage of consolidated net sales	2.60%	2.60%	2.60%	2.70%
Used Trailers | Commercial Trailer Products
Product Information [Line Items]
Net external sales	6,265	4,825	11,315	8,973
Used Trailers | Diversified Products
Product Information [Line Items]
Net external sales	671	293	1,620	293
Used Trailers | Retail
Product Information [Line Items]
Net external sales	3,657	4,294	6,305	7,731
Components, parts and service
Product Information [Line Items]
Net external sales	52,902	37,450	94,189	64,028
Percentage of consolidated net sales	12.80%	10.30%	12.80%	10.00%
Components, parts and service | Commercial Trailer Products
Product Information [Line Items]
Net external sales	2,592	814	5,401	1,373
Components, parts and service | Diversified Products
Product Information [Line Items]
Net external sales	30,515	20,433	49,314	34,683
Components, parts and service | Retail
Product Information [Line Items]
Net external sales	19,795	16,203	39,474	27,972
Equipment and other
Product Information [Line Items]
Net external sales	42,687	22,483	81,516	30,812
Percentage of consolidated net sales	10.30%	6.20%	11.10%	4.80%
Equipment and other | Commercial Trailer Products
Product Information [Line Items]
Net external sales	2,355	2,168	3,582	5,722
Equipment and other | Diversified Products
Product Information [Line Items]
Net external sales	38,942	19,321	75,260	24,073
Equipment and other | Retail
Product Information [Line Items]
Net external sales	$ 1,390	$ 994	$ 2,674	$ 1,017