Acquisition and Investment - ASV Stock Purchase - Schedule of Adjustments on Goodwill (Detail) - USD ($)
$ in Thousands
Dec. 31, 2016
Dec. 31, 2015
Jan. 15, 2015
Dec. 31, 2014
Dec. 19, 2014
Schedule Of Business Acquisitions Purchase Price Allocation [Line Items]          
Net impact on goodwill $ 70,248 $ 71,337 $ 30,173 $ 43,741  
ASV Inc [Member]          
Schedule Of Business Acquisitions Purchase Price Allocation [Line Items]          
Adjustment to reduce the value of certain inventory based on obtaining additional information         $ (26,757)
Eliminate value assigned to fixed assets determined not to exist at date of acquisition         (18,915)
Net impact on goodwill $ 30,579       $ 30,579
ASV Inc [Member] | Adjustment Based On Review Of Purchase Price Allocation          
Schedule Of Business Acquisitions Purchase Price Allocation [Line Items]          
Record liabilities that existed at acquisition date that had not been recorded       115  
Adjustment to reduce the value of certain inventory based on obtaining additional information       460  
Eliminate value assigned to fixed assets determined not to exist at date of acquisition       262  
Increase reserves for product liability suits based on additional information       3,199  
Adjustment to reserves for worker compensation claims based on additional information       68  
Adjustment to income tax payable to record tax liability based on additional information       (269)  
Net impact on goodwill       $ 3,835