Related Party Transactions - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	0 Months Ended		3 Months Ended	12 Months Ended	3 Months Ended	0 Months Ended
	Jan. 03, 2012	Oct. 03, 2011	Dec. 31, 2012	Dec. 31, 2011	Jun. 30, 2013 State and Local Jurisdiction	Oct. 03, 2011 Home and Security
Related Party Transaction [Line Items]
Dividend to Former Parent	$ 6.0	$ 48.9		$ 548.9		$ 500.0
Federal income tax portion to former parent			3.0
Proceeds from final settlement of 2011 income tax returns					1.2
Weighted-average interest rate on loans				3.40%
Related party interest expense				29.3
Related party interest income				6.1
Related party interest, net				$ (23.2)