Segment Reporting (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Segment Reporting Information [Line Items]
Revenues	$ 173,416	$ 180,291
Gross Profit	21,503	25,704
Depreciation and Amortization Expense	3,916	4,411
Selling, General & Administrative Expenses	16,619	16,790
Operating Income	4,557	8,580
Capital Expenditures	4,687	2,285
Other Items	3,125	888
Operating Segments
Segment Reporting Information [Line Items]
Revenues	173,416	180,291
Corporate/ Other
Segment Reporting Information [Line Items]
Revenues	(2,178)	(1,980)
Gross Profit	(357)	(425)
Depreciation and Amortization Expense	630	856
Selling, General & Administrative Expenses	6,683	5,804
Operating Income	(7,041)	(6,229)
Capital Expenditures	259	196
Other Items	2,377	687
Global Truck & Bus
Segment Reporting Information [Line Items]
Revenues	102,089	116,502
Global Truck & Bus | Operating Segments
Segment Reporting Information [Line Items]
Revenues	101,864	116,283
Gross Profit	14,038	17,823
Depreciation and Amortization Expense	2,063	2,034
Selling, General & Administrative Expenses	5,453	6,495
Operating Income	8,293	11,029
Capital Expenditures	3,212	904
Other Items	640	91
Global Truck & Bus | Intersegment Revenues
Segment Reporting Information [Line Items]
Revenues	225	219
Global Construction & Agriculture
Segment Reporting Information [Line Items]
Revenues	73,505	65,769
Global Construction & Agriculture | Operating Segments
Segment Reporting Information [Line Items]
Revenues	71,552	64,008
Gross Profit	7,822	8,306
Depreciation and Amortization Expense	1,223	1,521
Selling, General & Administrative Expenses	4,483	4,491
Operating Income	3,305	3,780
Capital Expenditures	1,216	1,185
Other Items	108	110
Global Construction & Agriculture | Intersegment Revenues
Segment Reporting Information [Line Items]
Revenues	$ 1,953	$ 1,761