Consolidating Financial Information - Schedule of Income Statement Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Sep. 30, 2014
Revenues:
Net consumer and other product sales	$ 1,088.8	$ 1,100.6
Oil and natural gas	34.3	35.5
Insurance premiums	11.7	13.9
Net investment income	230.8	201.2
Net investment gains	52.0	141.9
Insurance and investment product fees and other	20.8	16.9
Revenues	1,438.4	1,510.0
Operating costs and expenses:
Cost of consumer products and other goods sold	712.0	719.4
Oil and natural gas direct operating costs	20.5	16.1
Benefits and other changes in policy reserves	241.5	234.7
Selling, acquisition, operating and general expenses	365.4	317.1
Asset Impairment Charges			250.2
Impairment of Proved Oil and Gas Properties		0
Amortization of intangibles	31.8	43.4
Total operating costs and expenses	1,621.4	1,330.7
Operating income	(183.0)	179.3
Interest expense	(80.6)	(84.0)
Other income (expense), net	174.0	(11.9)
(Loss) income from continuing operations before income taxes	(89.6)	36.7
Income tax expense	16.8	38.3
Net income (loss)	(106.4)	(1.6)
Less: Net income attributable to noncontrolling interest	3.4	25.2
Net income (loss) attributable to controlling interest	(109.8)	(26.8)
Less: Preferred stock dividends and accretion		12.2
Net income (loss) attributable to common and participating preferred stockholders	(109.8)	(39.0)
Increase Decrease In Fair Value Of Equity Conversion Feature Of Preferred Stock	0	47.2
Gain on contingent purchase price reduction	0	0.5
Consolidated Entities [Member]
Revenues:
Net consumer and other product sales	1,088.8	1,100.6
Oil and natural gas		35.5
Insurance premiums	11.7	13.9
Net investment income	230.8	201.2
Net investment gains	52.0	141.9
Insurance and investment product fees and other	20.8	16.9
Revenues	1,438.4	1,510.0
Operating costs and expenses:
Cost of consumer products and other goods sold	712.0	719.4
Oil and natural gas direct operating costs		16.1
Benefits and other changes in policy reserves	241.5	234.7
Selling, acquisition, operating and general expenses	365.4	317.1
Asset Impairment Charges	250.2
Amortization of intangibles	31.8	43.4
Total operating costs and expenses	1,621.4	1,330.7
Operating income	(183.0)	179.3
Interest expense	(80.6)	(84.0)
Other income (expense), net	174.0	(11.9)
(Loss) income from continuing operations before income taxes	(89.6)
Income tax expense	16.8	38.3
Net income (loss)	(106.4)	(1.6)
Less: Net income attributable to noncontrolling interest	3.4	25.2
Net income (loss) attributable to controlling interest	(109.8)	(26.8)
Less: Preferred stock dividends and accretion		12.2
Net income (loss) attributable to common and participating preferred stockholders		(39.0)
Increase Decrease In Fair Value Of Equity Conversion Feature Of Preferred Stock		47.2
Gain on contingent purchase price reduction		0.5
Intersegment elimination [Member]
Revenues:
Net investment income	(4.1)	(3.7)
Net investment gains	0.6
Revenues	(3.5)	(3.7)
Operating costs and expenses:
Selling, acquisition, operating and general expenses	0.5
Total operating costs and expenses	0.5
Operating income	(4.0)	(3.7)
Equity in net income (losses) of subsidiaries	10.3	(71.5)
Affiliated interest income	(5.0)	(3.7)
Other income (expense), net	(2.2)
(Loss) income from continuing operations before income taxes	9.1	(71.5)
Income tax expense	1.7
Net income (loss)	7.4	(71.5)
Net income (loss) attributable to controlling interest	7.4	(71.5)
Net income (loss) attributable to common and participating preferred stockholders		(71.5)
Corporate and Other [Member]
Revenues:
Net consumer and other product sales	21.0
Revenues	21.0
Operating costs and expenses:
Cost of consumer products and other goods sold	14.4
Selling, acquisition, operating and general expenses	70.1	29.4
Asset Impairment Charges			60.2
Total operating costs and expenses	144.7	29.4
Operating income	(123.7)	(29.4)
Equity in net income (losses) of subsidiaries	(7.5)	71.5
Interest expense	(28.1)	(19.0)
Affiliated interest income	1.2
Other income (expense), net	17.4	(3.9)
(Loss) income from continuing operations before income taxes	(143.1)	(27.5)
Income tax expense	(13.2)	(0.7)
Net income (loss)	(129.9)	(26.8)
Less: Net income attributable to noncontrolling interest	(20.1)
Net income (loss) attributable to controlling interest	(109.8)	(26.8)
Less: Preferred stock dividends and accretion		12.2
Net income (loss) attributable to common and participating preferred stockholders		(39.0)
Increase Decrease In Fair Value Of Equity Conversion Feature Of Preferred Stock		47.2
Gain on contingent purchase price reduction		0.5
Other Financial Services [Member]
Operating costs and expenses:
Operating income	(1.1)	(3.9)
Asset Management segment [Member]
Revenues:
Net investment income	8.0	4.5
Revenues	8.0	4.5
Operating costs and expenses:
Selling, acquisition, operating and general expenses	9.1	8.4
Total operating costs and expenses	9.1	8.4
Operating income	(1.1)	(3.9)
Affiliated interest income	1.5	1.4
Other income (expense), net	(0.5)	(3.7)
(Loss) income from continuing operations before income taxes	(3.1)	(9.0)
Income tax expense		(0.2)
Net income (loss)	(3.1)	(8.8)
Less: Net income attributable to noncontrolling interest	(0.3)	(0.7)
Net income (loss) attributable to controlling interest	(2.8)	(8.1)
Net income (loss) attributable to common and participating preferred stockholders		(8.1)
Energy Segment [Member]
Revenues:
Oil and natural gas	34.3	35.5
Revenues	34.3	35.5
Operating costs and expenses:
Oil and natural gas direct operating costs	20.5	16.1
Selling, acquisition, operating and general expenses	18.8	13.4
Asset Impairment Charges			190.0
Total operating costs and expenses	229.3	29.5
Operating income	(195.0)	6.0
Interest expense	(2.2)	(2.4)
Affiliated interest income	2.3	2.3
Other income (expense), net	160.0	(3.4)
(Loss) income from continuing operations before income taxes	(39.5)	(2.1)
Net income (loss)	(39.5)	(2.1)
Less: Net income attributable to noncontrolling interest	(0.3)
Net income (loss) attributable to controlling interest	(39.2)	(2.1)
Net income (loss) attributable to common and participating preferred stockholders		(2.1)
Insurance Segment [Member]
Revenues:
Insurance premiums	11.7	13.9
Net investment income	226.9	200.4
Net investment gains	51.4	141.9
Insurance and investment product fees and other	20.8	16.9
Revenues	310.8	373.1
Operating costs and expenses:
Benefits and other changes in policy reserves	241.5	234.7
Selling, acquisition, operating and general expenses	32.8	29.9
Amortization of intangibles	11.3	23.2
Total operating costs and expenses	285.6	287.8
Operating income	25.2	85.3
Equity in net income (losses) of subsidiaries	(2.8)
Interest expense	(5.9)	(5.6)
(Loss) income from continuing operations before income taxes	16.5	79.7
Income tax expense	7.8	26.5
Net income (loss)	8.7	53.2
Less: Net income attributable to noncontrolling interest	3.3	3.3
Net income (loss) attributable to controlling interest	5.4	49.9
Net income (loss) attributable to common and participating preferred stockholders		49.9
Consumer Products Segment [Member]
Revenues:
Net consumer and other product sales	1,067.8	1,100.6
Revenues	1,067.8	1,100.6
Operating costs and expenses:
Cost of consumer products and other goods sold	697.6	719.4
Selling, acquisition, operating and general expenses	234.1	236.0
Amortization of intangibles	20.5	20.2
Total operating costs and expenses	952.2	975.6
Operating income	115.6	125.0
Interest expense	(44.4)	(57.0)
Other income (expense), net	(0.7)	(0.9)
(Loss) income from continuing operations before income taxes	70.5	67.1
Income tax expense	20.5	12.7
Net income (loss)	50.0	54.4
Less: Net income attributable to noncontrolling interest	20.8	22.6
Net income (loss) attributable to controlling interest	29.2	31.8
Net income (loss) attributable to common and participating preferred stockholders		$ 31.8