Acquisitions - Summary of Amounts Recorded in Connection with Acquisition of Business (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended																				0 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011	Apr. 06, 2011 FGL Provisional Valuation	Sep. 30, 2012 FGL Business Combination Measurement Period Adjustment	Sep. 30, 2012 FGL Final Measurement Period Valuation	Feb. 14, 2013 EXCO/HGI General Partner EXCO	Feb. 14, 2013 EXCO/HGI JV EXCO	Feb. 14, 2013 EXCO/HGI JV HGI	Feb. 14, 2013 EXCO/HGI JV	Mar. 05, 2013 Cotton-Valley Oil and Gas Properties HGI	Mar. 05, 2013 Cotton-Valley Oil and Gas Properties EXCO/HGI JV	Sep. 30, 2013 HHI Business	Dec. 17, 2012 HHI Business	Apr. 08, 2013 TLM Taiwan	Sep. 30, 2013 Hardware Acquisition Business Combination Measurement Period Adjustment	Dec. 17, 2012 Hardware Acquisition Business Combination Measurement Period Adjustment	Sep. 30, 2013 Shaser Biosciences, Inc.	Nov. 08, 2012 Shaser Biosciences, Inc.	Sep. 30, 2013 Shaser Biosciences, Inc. Business Combination Measurement Period Adjustment	Dec. 17, 2012 Minimum Trade Name HHI Business	Dec. 17, 2012 Minimum Customer relationships HHI Business
Business Acquisition [Line Items]
Estimated Income tax rate	35.00%																				17.00%	17.00%
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Cash									$ 0.1	$ 0.1	$ 0	$ 0	$ 24.0	$ 17.4	$ 0.8		$ 5.8	$ 0.9	$ 0.9	$ 0
Accounts receivable													108.6	104.6	0		4.0
Inventory													208.4	207.2	1.1		0.1
Prepaid expenses and other													9.3	13.3	2.2		(6.2)
Property, plant and equipment													138.4	104.5	36.8		(2.9)
Intangible asset													489.1	470.0	17.1	2.0	2.0	29.3	35.5	(6.2)
Other long-term assets				72.8	0	72.8			32.7	24.5	0	0	7.6	3.1	0.1		4.4	0.2	2.7	(2.5)
Total assets acquired													985.4	920.1	58.1		7.2	30.4	39.1	(8.7)
Accounts payable													138.1	130.1	0		8.0
Deferred tax liability - current													7.2	7.1	0		0.1
Accrued liabilities									(10.8)	(8.0)	0	0	(42.8)	(37.6)	(0.2)		(5.0)
Deferred tax liability - long-term													116.4	104.7	1.9		9.8
Other long-term liabilities									24.8	18.5	7.4	5.5	19.7	11.2	8.1		0.4
Total liabilities assumed													324.2	290.7	10.2		23.3	8.8	14.4	(5.6)
Total identifiable net assets				496.1	7.2	503.3			694.5	517.6	130.7	97.4	661.2	629.4	47.9		(16.1)	21.6	24.7	(3.1)
Non-controlling interests								(119.1)					(3.9)	(2.2)	0		(1.7)	(39.1)	(39.0)	(0.1)
Goodwill (Note 13)	1,476.7	694.2	610.3										717.8	662.1	45.6		10.1	67.2	63.9	3.3
Total net assets acquired													1,375.1	1,289.3	93.5		(7.7)	49.7	49.6	0.1
Oil and natural gas properties
Unproved oil and natural gas properties									65.1	48.5	7.2	5.4
Proved developed and undeveloped oil and natural gas properties									632.2	471.0	130.9	97.5
Total oil and natural gas properties									697.3	519.5	138.1	102.9
Business Acquisition Percentage Of Equity Interests Acquired							50.00%	24.50%	74.50%										56.00%
Preliminary working capital and other adjustments									30.5					(10.7)	(6.5)				(0.4)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Investments				17,705.4	0	17,705.4
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Reinsurance Recoverable				929.8	15.2	945.0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill				577.2	0	577.2
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Assets Noncurrent				256.6	(3.9)	252.7
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets				19,541.8	11.3	19,553.1
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Contractholder Liabilities				18,415.0	0	18,415.0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liability for Policy and Contract Claims				60.4	0	60.4
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt				95.0	0	95.0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other				475.3	4.1	479.4
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities				19,045.7	4.1	19,049.8
Business Combination Purchase Consideration Transferred				345.0	0	345.0		(725.0)	(349.8)	(574.8)
Business Combination Bargain Purchase Gains Recognized Amount				$ 151.1	$ 7.2	$ 158.3