Restructuring Expense (Restructuring Plan Reserve Recorded in Accrued Liabilities) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jul. 01, 2012	Jun. 30, 2013	Jul. 01, 2012
Restructuring Reserve [Roll Forward]
Restructuring expense	$ (5,297)	$ 6,220	$ (2,359)	$ 17,671
2011 Kansas City Restructuring Plan [Member] | Motorcycles And Related Products [Member]
Restructuring Reserve [Roll Forward]
Balance, beginning of period			2,259	4,123
Restructuring expense			0	0
Utilized—cash			(1,283)	0
Utilized—non-cash			0	0
Non-cash reserve release			(376)	(967)
Balance, end of period	600	3,156	600	3,156
2011 Kansas City Restructuring Plan [Member] | Employee Severance [Member] | Motorcycles And Related Products [Member]
Restructuring Reserve [Roll Forward]
Balance, beginning of period			2,259	4,123
Restructuring expense			0	0
Utilized—cash			(1,283)	0
Utilized—non-cash			0	0
Non-cash reserve release			(376)	(967)
Balance, end of period	600	3,156	600	3,156
2011 Kansas City Restructuring Plan [Member] | Other [Member] | Motorcycles And Related Products [Member]
Restructuring Reserve [Roll Forward]
Balance, beginning of period			0	0
Restructuring expense			0	0
Utilized—cash			0	0
Utilized—non-cash			0	0
Non-cash reserve release			0	0
Balance, end of period	0	0	0	0
2011 New Castalloy Restructuring Plan [Member] | Motorcycles And Related Products [Member]
Restructuring Reserve [Roll Forward]
Balance, beginning of period			9,451	8,733
Restructuring expense			3,530	5,989
Utilized—cash			(4,608)	(1,034)
Utilized—non-cash			(2,093)	(4,093)
Non-cash reserve release			(5,250)	0
Balance, end of period	1,030	9,595	1,030	9,595
2011 New Castalloy Restructuring Plan [Member] | Employee Severance [Member] | Motorcycles And Related Products [Member]
Restructuring Reserve [Roll Forward]
Balance, beginning of period			9,306	8,428
Restructuring expense			860	1,141
Utilized—cash			(4,019)	(312)
Utilized—non-cash			0	0
Non-cash reserve release			(5,250)	0
Balance, end of period	897	9,257	897	9,257
2011 New Castalloy Restructuring Plan [Member] | Other [Member] | Motorcycles And Related Products [Member]
Restructuring Reserve [Roll Forward]
Balance, beginning of period			145	305
Restructuring expense			577	755
Utilized—cash			(589)	(722)
Utilized—non-cash			0	0
Non-cash reserve release			0	0
Balance, end of period	133	338	133	338
2011 New Castalloy Restructuring Plan [Member] | Accelerated Depreciation [Member] | Motorcycles And Related Products [Member]
Restructuring Reserve [Roll Forward]
Balance, beginning of period			0	0
Restructuring expense			2,093	4,093
Utilized—cash			0	0
Utilized—non-cash			(2,093)	(4,093)
Non-cash reserve release			0	0
Balance, end of period	0	0	0	0
2011 Restructuring Plan [Member] | Motorcycles And Related Products [Member]
Restructuring Reserve [Roll Forward]
Balance, beginning of period			11,710	12,856
Restructuring expense			3,530	5,989
Utilized—cash			(5,891)	(1,034)
Utilized—non-cash			(2,093)	(4,093)
Non-cash reserve release			(5,626)	(967)
Balance, end of period	1,630	12,751	1,630	12,751
2010 Restructuring Plan [Member] | Employee Severance [Member] | Motorcycles And Related Products [Member]
Restructuring Reserve [Roll Forward]
Balance, beginning of period			10,156	20,361
Restructuring expense			0	3,457
Utilized—cash			(9,710)	(10,053)
Non-cash reserve release			(336)	0
Balance, end of period	110	13,765	110	13,765
2009 Restructuring Plan [Member] | Motorcycles And Related Products [Member]
Restructuring Reserve [Roll Forward]
Balance, beginning of period			5,357	10,089
Restructuring expense			1,606	11,219
Utilized—cash			(3,204)	(12,766)
Utilized—non-cash			0	0
Non-cash reserve release			(1,533)	(2,027)
Balance, end of period	2,226	6,515	2,226	6,515
2009 Restructuring Plan [Member] | Employee Severance [Member] | Motorcycles And Related Products [Member]
Restructuring Reserve [Roll Forward]
Balance, beginning of period			5,196	10,089
Restructuring expense			0	331
Utilized—cash			(1,613)	(1,878)
Utilized—non-cash			0	0
Non-cash reserve release			(1,533)	(2,027)
Balance, end of period	2,050	6,515	2,050	6,515
2009 Restructuring Plan [Member] | Other [Member] | Motorcycles And Related Products [Member]
Restructuring Reserve [Roll Forward]
Balance, beginning of period			161	0
Restructuring expense			1,606	10,888
Utilized—cash			(1,591)	(10,888)
Utilized—non-cash			0	0
Non-cash reserve release			0	0
Balance, end of period	176	0	176	0
2009 Restructuring Plan [Member] | Accelerated Depreciation [Member] | Motorcycles And Related Products [Member]
Restructuring Reserve [Roll Forward]
Balance, beginning of period			0	0
Restructuring expense			0	0
Utilized—cash			0	0
Utilized—non-cash			0	0
Non-cash reserve release			0	0
Balance, end of period	$ 0	$ 0	$ 0	$ 0