Segment and Georgraphic Data - Segment Information (Detail) (USD $)	3 Months Ended								12 Months Ended
	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Revenues:
Consolidated segment revenues									$ 5,963,000,000	$ 5,543,400,000	$ 4,480,700,000
Depreciation and amortization									302,600,000	358,700,000	268,300,000
Operating income (loss):
Consolidated operating income	144,900,000	229,100,000	16,200,000	179,300,000	205,400,000	182,600,000	134,000,000	215,400,000	569,500,000	737,400,000	409,500,000
Interest expense									(321,900,000)	(511,900,000)	(251,000,000)
Loss from the change in the fair value of the equity conversion feature of preferred stock									(12,700,000)	(101,600,000)	(156,600,000)
Gain on contingent purchase price reduction									500,000	0	41,000,000
Other expense, net									(22,200,000)	(5,600,000)	(17,500,000)
Income from continuing operations before income taxes									213,200,000	118,300,000	25,400,000
Capital expenditures									98,200,000	100,100,000	53,500,000
Total assets:
Consolidated total assets	30,100,200,000				27,908,800,000				30,100,200,000	27,908,800,000
Net change in cash due to operating activities
Consolidated change in cash due to operating activities									607,900,000	522,300,000	622,500,000
Net sales to external customers									4,449,200,000	4,085,600,000	3,252,400,000
Long-Lived Assets	908,600,000				993,300,000				908,600,000	993,300,000
Consumer Products Segment
Revenues:
Consolidated segment revenues									4,429,100,000	4,085,600,000	3,252,400,000
Depreciation and amortization									157,700,000	139,800,000	104,500,000
Operating income (loss):
Consolidated operating income									481,900,000	351,200,000	301,800,000
Interest expense									(202,100,000)	375,600,000	(191,900,000)
Loss from the change in the fair value of the equity conversion feature of preferred stock											0
Gain on contingent purchase price reduction									0		0
Other expense, net									(6,300,000)	(3,500,000)	(900,000)
Income from continuing operations before income taxes									273,500,000	(27,900,000)	109,000,000
Capital expenditures									73,400,000	81,900,000	46,800,000
Total assets:
Consolidated total assets	5,513,000,000				5,626,700,000				5,513,000,000	5,626,700,000
Net change in cash due to operating activities
Consolidated change in cash due to operating activities									432,700,000	256,500,000	258,700,000
Net sales to external customers									4,429,100,000	4,085,600,000	3,252,400,000
Long-Lived Assets	428,900,000				412,500,000				428,900,000	412,500,000
Insurance
Revenues:
Consolidated segment revenues									1,349,700,000	1,348,400,000	1,221,800,000
Depreciation and amortization									102,500,000	186,300,000	163,600,000
Operating income (loss):
Consolidated operating income									284,800,000	522,900,000	159,900,000
Interest expense									(22,500,000)	11,500,000	(2,500,000)
Loss from the change in the fair value of the equity conversion feature of preferred stock											0
Gain on contingent purchase price reduction									0		41,000,000
Other expense, net										(200,000)	100,000
Income from continuing operations before income taxes									256,300,000	511,200,000	198,500,000
Capital expenditures									9,400,000	4,100,000	6,200,000
Total assets:
Consolidated total assets	23,195,800,000				21,183,100,000				23,195,800,000	21,183,100,000
Net change in cash due to operating activities
Consolidated change in cash due to operating activities									288,100,000	336,200,000	300,000,000
Net sales to external customers
Long-Lived Assets	11,400,000				7,000,000				11,400,000	7,000,000
Energy Segment
Revenues:
Consolidated segment revenues									147,000,000	90,200,000	0
Depreciation and amortization									41,800,000	32,200,000	0
Operating income (loss):
Consolidated operating income									(53,700,000)	(45,200,000)	0
Interest expense									(7,700,000)	4,700,000	0
Loss from the change in the fair value of the equity conversion feature of preferred stock											0
Gain on contingent purchase price reduction									0		0
Other expense, net									(6,500,000)	(1,300,000)	0
Income from continuing operations before income taxes									(76,900,000)	(56,800,000)	0
Capital expenditures									13,400,000	13,400,000	0
Total assets:
Consolidated total assets	504,800,000				617,600,000				504,800,000	617,600,000
Net change in cash due to operating activities
Consolidated change in cash due to operating activities									44,300,000	37,200,000	0
Net sales to external customers
Long-Lived Assets	464,400,000				572,600,000				464,400,000	572,600,000
Asset Management segment [Member]
Operating income (loss):
Consolidated operating income									700,000	10,400,000
Interest expense
Loss from the change in the fair value of the equity conversion feature of preferred stock
Other expense, net									(1,200,000)
Income from continuing operations before income taxes									(6,500,000)	6,300,000
Net change in cash due to operating activities
Consolidated change in cash due to operating activities									(4,900,000)	11,700,000
Net sales to external customers
Other Segments [Member]
Revenues:
Consolidated segment revenues									34,200,000	28,900,000	8,600,000
Operating income (loss):
Consolidated operating income											2,500,000
Interest expense											0
Loss from the change in the fair value of the equity conversion feature of preferred stock											0
Gain on contingent purchase price reduction									0		0
Other expense, net											0
Income from continuing operations before income taxes											400,000
Total assets:
Consolidated total assets	692,500,000				572,200,000				692,500,000	572,200,000
Net change in cash due to operating activities
Net sales to external customers
Financial Services segment
Revenues:
Consolidated segment revenues									34,200,000	28,900,000	8,600,000
Depreciation and amortization									300,000	200,000	100,000
Operating income (loss):
Capital expenditures									900,000	300,000	500,000
Net change in cash due to operating activities
Consolidated change in cash due to operating activities											13,700,000
Long-Lived Assets	1,400,000				700,000				1,400,000	700,000
Intersegment elimination
Revenues:
Consolidated segment revenues									(17,100,000)	(9,700,000)	(2,100,000)
Operating income (loss):
Consolidated operating income									(17,700,000)	(10,900,000)	(2,100,000)
Interest expense											0
Loss from the change in the fair value of the equity conversion feature of preferred stock											0
Gain on contingent purchase price reduction									0		0
Other expense, net									(3,500,000)		0
Income from continuing operations before income taxes									(220,100,000)	(267,500,000)	(372,000,000)
Net change in cash due to operating activities
Net sales to external customers
Total segments
Revenues:
Depreciation and amortization									302,300,000	358,500,000	268,200,000
Operating income (loss):
Consolidated operating income									696,000,000	828,400,000	462,100,000
Capital expenditures									97,100,000	99,700,000	53,500,000
Net change in cash due to operating activities
Consolidated change in cash due to operating activities									760,200,000	641,600,000	572,400,000
Long-Lived Assets	906,100,000				992,800,000				906,100,000	992,800,000
Corporate Segment
Revenues:
Depreciation and amortization									300,000	200,000	100,000
Operating income (loss):
Capital expenditures									1,100,000	400,000	0
Net change in cash due to operating activities
Consolidated change in cash due to operating activities									(152,300,000)	(119,300,000)	50,100,000
Corporate expenses
Revenues:
Consolidated segment revenues									20,100,000
Operating income (loss):
Consolidated operating income									(126,500,000)	(91,000,000)	(52,600,000)
Interest expense									(89,600,000)	120,100,000	(56,600,000)
Loss from the change in the fair value of the equity conversion feature of preferred stock									(12,700,000)	(101,600,000)	(156,600,000)
Gain on contingent purchase price reduction									500,000		0
Other expense, net									(4,700,000)	(600,000)	(16,700,000)
Income from continuing operations before income taxes									(13,100,000)	(47,000,000)	89,500,000
Total assets:
Consolidated total assets	2,933,100,000				2,383,500,000				2,933,100,000	2,383,500,000
Net change in cash due to operating activities
Net sales to external customers									20,100,000
Consolidated Entities
Revenues:
Consolidated segment revenues									5,942,900,000	5,543,400,000	4,480,700,000
Operating income (loss):
Consolidated operating income										737,400,000	409,500,000
Interest expense										511,900,000	(251,000,000)
Loss from the change in the fair value of the equity conversion feature of preferred stock										(101,600,000)	(156,600,000)
Gain on contingent purchase price reduction											41,000,000
Other expense, net										(5,600,000)	(17,500,000)
Income from continuing operations before income taxes										118,300,000	25,400,000
Total assets:
Consolidated total assets	30,100,200,000				27,908,800,000				30,100,200,000	27,908,800,000
Net change in cash due to operating activities
Net sales to external customers										4,085,600,000	3,252,400,000
Corporate assets
Net change in cash due to operating activities
Long-Lived Assets	2,500,000				500,000				2,500,000	500,000
UNITED STATES
Operating income (loss):
Income from continuing operations before income taxes									9,200,000	(78,900,000)	(146,500,000)
Net change in cash due to operating activities
Net sales to external customers									2,660,800,000	2,411,400,000	1,772,100,000
Long-Lived Assets	733,000,000				811,600,000				733,000,000	811,600,000
Outside of the United States
Operating income (loss):
Income from continuing operations before income taxes									204,000,000	197,200,000	171,900,000
Net change in cash due to operating activities
Net sales to external customers									1,788,400,000	1,674,200,000	1,480,300,000
Long-Lived Assets	$ 175,600,000				$ 181,700,000				$ 175,600,000	$ 181,700,000