Segment Data - Segment Information (Detail) (USD $)	3 Months Ended		9 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Sep. 30, 2013
Segment Reporting Information [Line Items]
Document Period End Date			Jun. 30, 2014
Revenues:
Consolidated revenues	$ 1,599,400,000	$ 1,409,200,000	$ 4,450,600,000	$ 4,042,600,000
Operating income (loss):
Consolidated operating income	229,100,000	182,600,000	424,600,000	532,000,000
Interest expense	(77,900,000)	(83,900,000)	(239,100,000)	(302,700,000)
Gain (loss) from the change in the fair value of the equity conversion feature of preferred stock	38,000,000	52,600,000	(12,700,000)	81,900,000
Gain on contingent purchase price reduction			500,000	0
Other income (expense), net	6,000,000	4,200,000	(10,500,000)	(7,700,000)
Income from continuing operations before income taxes	195,200,000	155,500,000	162,800,000	303,500,000
Total assets:
Consolidated total assets	29,885,200,000		29,885,200,000		27,908,800,000
Total cash provided from operating activities:
Consolidated cash provided from operating activities			164,400,000	94,000,000
Total segments [Member]
Revenues:
Consolidated revenues	1,594,700,000	1,409,200,000	4,445,900,000	4,042,600,000
Operating income (loss):
Consolidated operating income	267,000,000	200,100,000	522,800,000	600,400,000
Total cash provided from operating activities:
Consolidated cash provided from operating activities			262,100,000	178,700,000
Intersegment elimination [Member]
Revenues:
Consolidated revenues	(2,200,000)	(5,200,000)	(9,500,000)	(6,100,000)
Operating income (loss):
Consolidated operating income	(2,000,000)	(6,100,000)	(9,700,000)	(6,100,000)
Interest expense				(233,000,000)
Gain (loss) from the change in the fair value of the equity conversion feature of preferred stock
Gain on contingent purchase price reduction			0
Other income (expense), net			(4,100,000)
Income from continuing operations before income taxes			(160,300,000)	(233,000,000)
Other Financial Services [Member]
Operating income (loss):
Consolidated operating income	3,100,000	2,400,000
Asset Management segment [Member]
Revenues:
Consolidated revenues	11,300,000	7,100,000	25,600,000	20,800,000
Operating income (loss):
Consolidated operating income			3,200,000	10,200,000
Interest expense
Gain (loss) from the change in the fair value of the equity conversion feature of preferred stock
Gain on contingent purchase price reduction			0
Other income (expense), net			(700,000)	(900,000)
Income from continuing operations before income taxes			(1,900,000)	6,600,000
Total assets:
Consolidated total assets	700,900,000		700,900,000		572,200,000
Total cash provided from operating activities:
Consolidated cash provided from operating activities			(1,200,000)	2,600,000
Energy Segment [Member]
Revenues:
Consolidated revenues	37,600,000	37,800,000	112,300,000	54,500,000
Operating income (loss):
Consolidated operating income	8,600,000	4,800,000	(57,200,000)	5,300,000
Interest expense			(5,900,000)
Gain (loss) from the change in the fair value of the equity conversion feature of preferred stock
Gain on contingent purchase price reduction			0
Other income (expense), net			(12,400,000)	800,000
Income from continuing operations before income taxes			(82,300,000)	(100,000)
Total assets:
Consolidated total assets	513,400,000		513,400,000		617,600,000
Total cash provided from operating activities:
Consolidated cash provided from operating activities			34,800,000	20,800,000
Insurance [Member]
Revenues:
Consolidated revenues	419,500,000	279,700,000	1,066,700,000	1,025,600,000
Operating income (loss):
Consolidated operating income	108,600,000	83,300,000	220,200,000	354,900,000
Interest expense			(16,900,000)
Gain (loss) from the change in the fair value of the equity conversion feature of preferred stock
Gain on contingent purchase price reduction			0
Other income (expense), net				200,000
Income from continuing operations before income taxes			201,700,000	349,200,000
Total assets:
Consolidated total assets	22,887,200,000		22,887,200,000		21,183,100,000
Total cash provided from operating activities:
Consolidated cash provided from operating activities			279,400,000	230,900,000
Consumer Products Segment [Member]
Revenues:
Consolidated revenues	1,128,500,000	1,089,800,000	3,250,800,000	2,947,800,000
Operating income (loss):
Consolidated operating income	148,700,000	115,700,000	366,300,000	236,100,000
Interest expense			(151,700,000)
Gain (loss) from the change in the fair value of the equity conversion feature of preferred stock
Gain on contingent purchase price reduction			0
Other income (expense), net			(4,400,000)	(7,900,000)
Income from continuing operations before income taxes			210,200,000	36,400,000
Total assets:
Consolidated total assets	5,697,100,000		5,697,100,000		5,626,700,000
Total cash provided from operating activities:
Consolidated cash provided from operating activities			(50,900,000)	(75,600,000)
Corporate expenses [Member]
Revenues:
Consolidated revenues	4,700,000		4,700,000
Operating income (loss):
Consolidated operating income	(37,900,000)	(17,500,000)	(98,200,000)	(68,400,000)
Interest expense			(64,600,000)	233,000,000
Gain (loss) from the change in the fair value of the equity conversion feature of preferred stock			(12,700,000)	81,900,000
Gain on contingent purchase price reduction			500,000
Other income (expense), net			11,100,000	100,000
Income from continuing operations before income taxes			(4,600,000)	144,400,000
Total assets:
Consolidated total assets	2,840,700,000		2,840,700,000		2,383,500,000
Corporate Segment [Member]
Total cash provided from operating activities:
Consolidated cash provided from operating activities			$ (97,700,000)	$ (84,700,000)