Segment Reporting and Geographic Locations - Sales by Segment (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Schedule Of Sales Revenue By Business Segment [Line Items]
Revenues	$ 184,692	$ 202,729	$ 217,617	$ 220,303	$ 211,874	$ 213,802	$ 215,996	$ 198,071	$ 825,341	$ 839,743	$ 747,718
Gross Profit	24,352	27,890	29,506	29,074	26,773	28,426	28,185	24,304	110,822	107,688	79,729
Depreciation and Amortization Expense									17,710	18,247	20,583
Selling, General & Administrative Expenses									71,469	72,480	71,711
Operating Income	$ 5,294	$ 9,946	$ 11,588	$ 11,198	$ 9,494	$ 9,705	$ 9,047	$ 5,448	38,026	33,693	6,438
Capital Expenditures									15,590	14,569	13,659
Other Items 1									2,332	2,090	9,802
Restructuring charges									2,332	1,321
External Revenues
Schedule Of Sales Revenue By Business Segment [Line Items]
Revenues									825,341	839,743	747,718
Intersegment Revenues
Schedule Of Sales Revenue By Business Segment [Line Items]
Revenues									0	0	0
Global Truck & Bus
Schedule Of Sales Revenue By Business Segment [Line Items]
Equipment transfer expense									1,800
Impairment charges										1,300	1,300
Loss on sale of manufacturing facility										800
Severance costs											600
Global Construction & Agriculture
Schedule Of Sales Revenue By Business Segment [Line Items]
Severance costs											300
IT Software
Schedule Of Sales Revenue By Business Segment [Line Items]
Impairment charges											1,300
Operating Segments | Global Truck & Bus
Schedule Of Sales Revenue By Business Segment [Line Items]
Revenues									565,269	534,118	473,244
Gross Profit									85,702	81,430	59,524
Depreciation and Amortization Expense									8,909	8,973	11,773
Selling, General & Administrative Expenses									25,263	28,890	28,036
Operating Income									59,252	51,171	30,056
Capital Expenditures									7,579	8,055	5,891
Other Items 1									1,838	2,090	3,221
Operating Segments | Global Truck & Bus | External Revenues
Schedule Of Sales Revenue By Business Segment [Line Items]
Revenues									564,651	533,752	472,878
Operating Segments | Global Truck & Bus | Intersegment Revenues
Schedule Of Sales Revenue By Business Segment [Line Items]
Revenues									618	366	366
Operating Segments | Global Construction & Agriculture
Schedule Of Sales Revenue By Business Segment [Line Items]
Revenues									271,627	317,201	282,837
Gross Profit									28,627	29,583	24,365
Depreciation and Amortization Expense									5,855	5,905	5,459
Selling, General & Administrative Expenses									20,442	21,903	19,273
Operating Income									8,044	7,533	4,943
Capital Expenditures									4,688	5,140	6,118
Other Items 1									494	0	272
Operating Segments | Global Construction & Agriculture | External Revenues
Schedule Of Sales Revenue By Business Segment [Line Items]
Revenues									260,690	305,991	274,840
Operating Segments | Global Construction & Agriculture | Intersegment Revenues
Schedule Of Sales Revenue By Business Segment [Line Items]
Revenues									10,937	11,210	7,997
Corporate/ Other
Schedule Of Sales Revenue By Business Segment [Line Items]
Revenues									(11,555)	(11,576)	(8,363)
Gross Profit									(3,507)	(3,325)	(4,160)
Depreciation and Amortization Expense									2,946	3,369	3,351
Selling, General & Administrative Expenses									25,764	21,687	24,402
Operating Income									(29,270)	(25,011)	(28,561)
Capital Expenditures									3,323	1,374	1,650
Other Items 1									0	0	6,309
Severance costs											1,000
Charges associated with hiring new CEO											5,300
Corporate/ Other | External Revenues
Schedule Of Sales Revenue By Business Segment [Line Items]
Revenues									0	0	0
Corporate/ Other | Intersegment Revenues
Schedule Of Sales Revenue By Business Segment [Line Items]
Revenues									(11,555)	$ (11,576)	$ (8,363)
Employee Severance and Lease Cancellation | Global Construction & Agriculture
Schedule Of Sales Revenue By Business Segment [Line Items]
Restructuring charges									$ 500