Debt - Schedule of Debt (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified	Dec. 27, 2014	Sep. 08, 2014	Jan. 17, 2014	Dec. 28, 2013	Jan. 31, 2012
Senior Notes [Member]
Debt Instrument [Line Items]
Long-term debt, face value	$ 625.0	$ 115.0	$ 260.0	$ 250.0	$ 250.0
Original issuance discount	26.5			4.0
Credit Facility [Member]
Debt Instrument [Line Items]
Long-term debt, face value	415.7			419.9
Original issuance discount	$ 2.3			$ 2.9