Schedule V Valuation and Qualifying Accounts (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Allowance for Loan and Lease Losses, Real Estate [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	$ 0.3		$ 0.3		$ 0.3
Additions Charged to Costs and Expenses	0		0		0
Additions Charged to Other Accounts	0		0		0
Deductions	0	[1]	0	[1]	0	[1]
Balance at End of Period	0.3		0.3		0.3
Allowance for Doubtful Accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	5.7		7.2		9.9
Additions Charged to Costs and Expenses	0.9		1.3		1.1
Additions Charged to Other Accounts	0		0		0
Deductions	0.4	[1]	2.8	[1]	3.8	[1]
Balance at End of Period	$ 6.2		$ 5.7		$ 7.2

[1] Deductions include amounts deemed to reduce exposure of probable losses, amounts deemed uncollectible, and amounts related to fluctuations in the foreign currency exchange rate.