Restructuring Expense (Restructuring Plan Reserve Recorded in Accrued Liabilities) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 28, 2014	Sep. 29, 2013	Sep. 28, 2014	Sep. 29, 2013
Restructuring Reserve [Roll Forward]
Restructuring expense	$ 0	$ 646	$ 0	$ (1,713)
2011 Kansas City Restructuring Plan [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense			6,000
2011 New Castalloy Restructuring Plan [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense			22,100
2010 Restructuring Plan [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense			59,200
2009 Restructuring Plan [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense			393,800
Non-cash reserve release				(1,531)
Motorcycles [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense	0	646	0	(1,713)
Motorcycles [Member] | 2011 Kansas City Restructuring Plan [Member] | Employee Severance [Member]
Restructuring Reserve [Roll Forward]
Balance, beginning of period				2,259
Restructuring expense				0
Utilized—cash				(1,283)
Utilized—non-cash				0
Non-cash reserve release				(976)
Motorcycles [Member] | 2011 Kansas City Restructuring Plan [Member] | Other [Member]
Restructuring Reserve [Roll Forward]
Balance, beginning of period				0
Restructuring expense				0
Utilized—cash				0
Utilized—non-cash				0
Non-cash reserve release				0
Motorcycles [Member] | 2011 New Castalloy Restructuring Plan [Member] | Employee Severance [Member]
Restructuring Reserve [Roll Forward]
Balance, beginning of period				9,306
Restructuring expense				1,361
Utilized—cash				(5,360)
Utilized—non-cash				0
Non-cash reserve release				(5,250)
Motorcycles [Member] | 2011 New Castalloy Restructuring Plan [Member] | Other [Member]
Restructuring Reserve [Roll Forward]
Balance, beginning of period				145
Restructuring expense				590
Utilized—cash				(602)
Utilized—non-cash				0
Non-cash reserve release				0
Motorcycles [Member] | 2011 New Castalloy Restructuring Plan [Member] | Accelerated Depreciation [Member]
Restructuring Reserve [Roll Forward]
Balance, beginning of period				0
Restructuring expense				2,093
Utilized—cash				0
Utilized—non-cash				(2,093)
Non-cash reserve release				0
Motorcycles [Member] | 2010 Restructuring Plan [Member] | Employee Severance [Member]
Restructuring Reserve [Roll Forward]
Balance, beginning of period				10,156
Restructuring expense				0
Utilized—cash				(9,710)
Non-cash reserve release				(446)
Balance, end of period		0		0
Motorcycles [Member] | 2009 Restructuring Plan [Member]
Restructuring Reserve [Roll Forward]
Balance, beginning of period				5,357
Restructuring expense				2,446
Utilized—cash				(4,227)
Balance, end of period		2,045		2,045
Motorcycles [Member] | 2009 Restructuring Plan [Member] | Employee Severance [Member]
Restructuring Reserve [Roll Forward]
Balance, beginning of period				5,196
Restructuring expense				0
Utilized—cash				(1,620)
Non-cash reserve release				(1,531)
Balance, end of period		2,045		2,045
Motorcycles [Member] | 2009 Restructuring Plan [Member] | Other [Member]
Restructuring Reserve [Roll Forward]
Balance, beginning of period				161
Restructuring expense				2,446
Utilized—cash				(2,607)
Non-cash reserve release				0
Balance, end of period		0		0
Motorcycles [Member] | 2009 Restructuring Plan [Member] | Accelerated Depreciation [Member]
Restructuring Reserve [Roll Forward]
Balance, beginning of period				0
Restructuring expense				0
Utilized—cash				0
Non-cash reserve release				0
Balance, end of period		$ 0		$ 0