Goodwill and Other Intangible Assets - Goodwill and Other Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2013	Jul. 01, 2012	Jun. 30, 2013	Jul. 01, 2012	Dec. 31, 2012	Jan. 01, 2012
Other intangible assets, net
Balance, Beginning period			$ 12,765	$ 22,907	$ 22,907
Less: Amortization	(1,600)	(2,500)	(3,081)	(5,300)	(10,142)
Balance, Ending period	9,684		9,684		12,765
Goodwill
Balance	81,598		81,598		81,598	81,598
Balance	81,598		81,598		81,598	81,598
Transportation [Member]
Other intangible assets, net
Balance, Beginning period			5,768	11,243	11,243
Less: Amortization			(1,409)		(5,475)
Balance, Ending period	4,359		4,359		5,768
Goodwill
Balance	59,334		59,334		59,334	59,334
Balance	59,334		59,334		59,334	59,334
Federal [Member]
Other intangible assets, net
Balance, Beginning period			6,997	11,664	11,664
Less: Amortization			(1,672)		(4,667)
Balance, Ending period	5,325		5,325		6,997
Goodwill
Balance	22,264		22,264		22,264	22,264
Balance	$ 22,264		$ 22,264		$ 22,264	$ 22,264