Inventories (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Inventory [Line Items]
Raw materials and components	$ 64,825	$ 57,187
Work in progress	26,303	24,849
Finished goods	126,909	82,930
Aftermarket parts	10,256	9,882
Used trailers	15,395	14,639
Total, Inventories	$ 243,688	$ 189,487