Basis of Presentation, Significant Accounting Polices and Practicies and Recent Accounting Pronouncements Basis of Presentation - Additional Information (Details) $ / shares in Units, $ in Millions	3 Months Ended			6 Months Ended	9 Months Ended
	Jun. 30, 2016 USD ($) $ / shares	Mar. 31, 2016 USD ($) $ / shares	Jun. 30, 2015 USD ($) $ / shares	Mar. 31, 2016 USD ($) $ / shares	Jun. 30, 2016 USD ($) $ / shares $ / MMBTU	Jun. 30, 2015 USD ($) $ / shares	Dec. 31, 2015 USD ($)	Sep. 30, 2015 USD ($)
Basis of Presentation [Line Items]
Earnings Per Share, Diluted | $ / shares	$ (0.66)	$ (0.12)	$ (0.38)	$ (0.30)	$ (0.95)	$ (2.09)
Discontinued Operation, Income (Loss) from Discontinued Operation, Net of Tax, Per Diluted Share | $ / shares	(1.04)		0.44		(1.34)	0.55
Income (Loss) from Continuing Operations, Per Diluted Share | $ / shares	0.38	(0.01)	(0.82)	0.04	0.39	(2.64)
Earnings Per Share, Basic | $ / shares	(0.67)	(0.12)	(0.38)	(0.30)	(0.97)	(2.09)
Discontinued Operation, Income (Loss) from Discontinued Operation, Net of Tax, Per Basic Share | $ / shares	(1.06)		0.44		(1.37)	0.55
Income (Loss) from Continuing Operations, Per Basic Share | $ / shares	$ 0.39	$ (0.01)	$ (0.82)	$ 0.04	$ 0.40	$ (2.64)
Net Income (Loss) Attributable to Parent	$ (132.9)	$ (24.7)	$ (75.6)	$ (58.6)	$ (191.5)	$ (413.7)
Less: Net income attributable to noncontrolling interest	39.9	40.6	34.2	81.5	121.4	28.4
Net loss	(93.0)	15.9	(41.4)	22.9	(70.1)	(385.3)
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	(208.4)		102.9		(257.1)	125.7
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	115.4	29.0	(144.3)	71.6	187.0	(511.0)
Income tax benefit	(8.4)	$ (8.5)	(37.8)	$ (6.6)	$ (15.0)	(32.6)
Document Period End Date					Jun. 30, 2016
Deferred Finance Costs, Net	91.6				$ 91.6			$ 102.9
Asset Impairment Charges	15.7		112.6		106.5	577.0
Impairment of Proved Oil and Gas Properties					93.2	439.4
Energy Segment [Member]
Basis of Presentation [Line Items]
Net Income (Loss) Attributable to Parent					(19.7)	(321.1)
Less: Net income attributable to noncontrolling interest						(0.8)
Net loss					(19.7)	(321.9)
Asset Impairment Charges	$ 17.6		$ 102.8		$ 93.2	$ 439.4
FGL [Member]
Basis of Presentation [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	19.60%				19.60%
Statutory Accounting Practices, Statutory Capital and Surplus, Increase (Decrease) as a Result of ReDomestication by Entity	$ 26.2				$ 26.2
Raven Re [Member]
Basis of Presentation [Line Items]
Statutory Accounting Practices, Statutory Capital and Surplus, Balance	207.5				207.5			226.3
Statutory Accounting Practices, Permitted Practice, Change in Statutory Capital and Surplus	3.2				3.2			2.5
Statutory Accounting Practices, Non-Permitted Practice, Change in Statutory Capital and Surplus	0.1				0.1			33.1
Statutory Accounting Practices, Statutory Capital and Surplus, Change in Permitted Practice to Non-Permitted, Balance	210.6				$ 210.6			195.6
Natural Gas [Member]
Basis of Presentation [Line Items]
Average Sales Prices | $ / MMBTU					2.24
Accounting Standards Update 2015-17 [Member]
Basis of Presentation [Line Items]
Deferred Tax Assets, Net	$ 39.1				$ 39.1
Accounting Standards Update 2016-09 [Domain]
Basis of Presentation [Line Items]
Unrecognized Tax Benefits that Would Result in Deferred Tax Assets							$ (4.3)	$ (28.4)
Goodwill [Member]
Basis of Presentation [Line Items]
Goodwill, Purchase Accounting Adjustments					$ 3.4
Restatement Adjustment [Member]
Basis of Presentation [Line Items]
Earnings Per Share, Diluted | $ / shares		$ 0.05		$ 0.05
Income (Loss) from Continuing Operations, Per Diluted Share | $ / shares		0.09		0.09
Earnings Per Share, Basic | $ / shares		0.05		0.05
Income (Loss) from Continuing Operations, Per Basic Share | $ / shares		$ 0.09		$ 0.09
Net Income (Loss) Attributable to Parent		$ 10.1		$ 10.1
Less: Net income attributable to noncontrolling interest		7.3		7.3
Net loss		17.4		17.4
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest		17.4		17.4
Income tax benefit		$ (17.4)		$ (17.4)
Scenario, Previously Reported [Member]
Basis of Presentation [Line Items]
Earnings Per Share, Diluted | $ / shares		$ (0.18)		$ (0.35)
Income (Loss) from Continuing Operations, Per Diluted Share | $ / shares		(0.10)		(0.05)
Earnings Per Share, Basic | $ / shares		(0.18)		(0.35)
Income (Loss) from Continuing Operations, Per Basic Share | $ / shares		$ (0.10)		$ (0.05)
Net Income (Loss) Attributable to Parent		$ (34.8)		$ (68.7)
Less: Net income attributable to noncontrolling interest		33.3		74.2
Net loss		(1.5)		5.5
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest		11.6		54.2
Income tax benefit		$ 8.9		$ 10.8