Nature of Operations and Accounting Policies - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	1 Months Ended							1 Months Ended
	Oct. 03, 2012 Buses	Dec. 20, 2012 Buses	Dec. 20, 2012 Buses Trademarks	Oct. 03, 2012 Buses Trademarks	Dec. 20, 2012 Buses Dealer Networks	Oct. 03, 2012 Buses Dealer Networks	Dec. 20, 2012 Buses Backlog	Sep. 30, 2011 Minimum
Significant Accounting Policies [Line Items]
Percentage used to determine whether it is more likely than not that a reporting unit's fair value is less than its carrying amount								50.00%
Cash paid for acquisition	$ 3,914	$ 6,804
Business acquisition allocated to inventory	915	804
Business acquisition allocated to property and equipment	331	630
Business acquisition allocated to goodwill	768	4,495
Business acquisition allocated to amortizing intangible asset			670	1,000	410	900	20
Asset purchase agreement date	Sep. 17, 2012
Business acquisition allocated to Certain liabilities		$ 225