Restructuring Expense (Restructuring Plan Reserve Recorded in Accrued Liabilities Related to 2011 Plan) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Apr. 01, 2012
Restructuring Cost and Reserve [Line Items]
Restructuring expense	$ 2,938	$ 11,451
2011 Kansas City Restructuring Plan [Member] | Motorcycles And Related Products [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	0	542
Restructuring Reserve, Settled with Cash	0	0
Balance, beginning of period	2,259	4,123
Balance, end of period	1,469	4,665
Restructuring Reserve, Settled without Cash	(790)	0
2011 Kansas City Restructuring Plan [Member] | Employee Serverance And Termination Costs [Member] | Motorcycles And Related Products [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	0	542
Restructuring Reserve, Settled with Cash	0	0
Balance, beginning of period	2,259	4,123
Balance, end of period	1,469	4,665
Restructuring Reserve, Settled without Cash	(790)	0
2011 Kansas City Restructuring Plan [Member] | Other [Member] | Motorcycles And Related Products [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	0	0
Restructuring Reserve, Settled with Cash	0	0
Balance, beginning of period	0	0
Balance, end of period	0	0
Restructuring Reserve, Settled without Cash	0	0
2011 New Castalloy Restructuring Plan [Member] | Motorcycles And Related Products [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	3,010	3,019
Restructuring Reserve, Settled with Cash	(1,872)	(517)
Balance, beginning of period	9,451	8,733
Balance, end of period	8,497	9,136
Restructuring Reserve, Settled without Cash	(2,092)	(2,099)
2011 New Castalloy Restructuring Plan [Member] | Employee Serverance And Termination Costs [Member] | Motorcycles And Related Products [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	474	571
Restructuring Reserve, Settled with Cash	(1,416)	(156)
Balance, beginning of period	9,306	8,428
Balance, end of period	8,364	8,843
Restructuring Reserve, Settled without Cash	0	0
2011 New Castalloy Restructuring Plan [Member] | Other [Member] | Motorcycles And Related Products [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	444	349
Restructuring Reserve, Settled with Cash	(456)	(361)
Balance, beginning of period	145	305
Balance, end of period	133	293
Restructuring Reserve, Settled without Cash	0	0
2011 New Castalloy Restructuring Plan [Member] | Accelerated Depreciation [Member] | Motorcycles And Related Products [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	2,092	2,099
Restructuring Reserve, Settled with Cash	0	0
Balance, beginning of period	0	0
Balance, end of period	0	0
Restructuring Reserve, Settled without Cash	(2,092)	(2,099)
2011 Restructuring Plan [Member] | Motorcycles And Related Products [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	3,010	3,561
Restructuring Reserve, Settled with Cash	(1,872)	(517)
Balance, beginning of period	11,710	12,856
Balance, end of period	9,966	13,801
Restructuring Reserve, Settled without Cash	$ (2,882)	$ (2,099)