Investments Mortgage Loan Restructuring (Detail) (Commercial Real Estate Portfolio Segment [Member], USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Jun. 30, 2012
Second Quarter
Financing Receivable, Modifications [Line Items]
Carrying Amount of Troubled Debt Modifications Entered Into During Period	$ 4.3	$ 8.9
Number of Trouble Debt Modifications Entered Into During Period	1	1
First and Second Quarters
Financing Receivable, Modifications [Line Items]
Carrying Amount of Troubled Debt Modifications Entered Into During Period	$ 4.3	$ 13.1
Number of Trouble Debt Modifications Entered Into During Period	1	2