Acquisitions - Company's Pro Forma Results (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2013	Apr. 01, 2012	Mar. 31, 2013	Apr. 01, 2012
Revenues:
Pro forma revenues	$ 1,429.0	$ 1,376.3	$ 2,879.7	$ 2,817.9
Net income:
Pro forma net income	(51.4)	7.0	22.0	68.8
Basic net income per common share attributable to controlling interest:
Pro forma net income per common share (in dollars per share)	$ (0.34)	$ 0.02	$ 0.12	$ 0.27
Diluted (in dollars per share)	$ (0.33)	$ (0.03)	$ 0.06	$ 0.10
Basic (in dollars per share)	$ (0.33)	$ (0.03)	$ 0.08	$ 0.10
Pro forma diluted net income per common share (in dollars per share)	$ (0.34)	$ 0.02	$ 0.08	$ 0.27
Reported Revenues [Member]
Revenues:
Pro forma revenues	1,411.9	1,105.7	2,634.2	2,271.7
Net income:
Pro forma net income	(50.5)	(0.2)	17.6	45.3
HHI Business [Member] | HHI adjustment [Member]
Revenues:
Pro forma revenues		232.2	191.8	463.9
Net income:
Pro forma net income		10.1	4.9	23.1
Basic net income per common share attributable to controlling interest:
Pro forma net income per common share (in dollars per share)		$ 0.07	$ 0.04	$ 0.17
Pro forma diluted net income per common share (in dollars per share)		$ 0.07	$ 0.02	$ 0.17
EXCO/HGI Partnership [Member] | HHI adjustment [Member]
Revenues:
Pro forma revenues	17.1	38.4	53.7	82.3
Net income:
Pro forma net income	$ (0.9)	$ (2.9)	$ (0.5)	$ 0.4
Basic net income per common share attributable to controlling interest:
Pro forma net income per common share (in dollars per share)	$ (0.01)	$ (0.02)	$ 0.00	$ 0.00
Pro forma diluted net income per common share (in dollars per share)	$ (0.01)	$ (0.02)	$ 0.00	$ 0.00