Discontinued Operations (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Discontinued Operations [Line Items}
Net (loss) income from sale of discontinued operations	$ (0.1)	$ 2.7	$ 7.9	$ 2.7
Net loss from discontinued operations, net of tax	(0.2)	(0.1)	(0.3)	(0.6)
Other revenue	87.5	6.4	123.3	3.0
Segment, Discontinued Operations
Discontinued Operations [Line Items}
Net (loss) income from sale of discontinued operations	0.1	2.7	8.0	2.7
Esurance | Segment, Discontinued Operations
Discontinued Operations [Line Items}
Income Taxes Paid	0.3
OneBeacon Runoff [Member]
Discontinued Operations [Line Items}
Net (loss) income from sale of discontinued operations	5.3			5.3
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax	8.2			8.2
Reserve charge under the SPA, before tax		7.4	$ 7.4
Reserve Charge After-Tax		$ 4.8		$ 4.8
OneBeacon Runoff [Member] | Segment, Discontinued Operations
Discontinued Operations [Line Items}
Net (loss) income from sale of discontinued operations	$ 0.3