Goodwill and Intangibles, including DAC and VOBA - Estimated Amortization Expense for VOBA and DAC in Future Fiscal Periods (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013
Schedule Of Amortization Expense And Weighted Average Lives Of Identified Intangible Assets [Line Items]
2013	$ 80.7
2014	80.7
2015	80.7
2016	80.7
2017	80.7
VOBA [Member]
Schedule Of Amortization Expense And Weighted Average Lives Of Identified Intangible Assets [Line Items]
2013	33.4
2014	44.8
2015	39.5
2016	32.2
2017	25.9
Thereafter	$ 117.6