Restructuring and Other Charges, Net - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
Dec. 31, 2011 Positions	Sep. 30, 2012 Strategic Initiative [Member]
Restructuring Cost and Reserve [Line Items]
Pre-tax restructuring charge, net		$ 1.7
Severance costs	$ 9.8
Number of positions eliminated	72

Net total Increase or Decrease in the accrual for restructuring costs during the reporting period.

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The charge against earnings in the period for known and estimated costs of termination benefits provided to current employees that are involuntarily terminated under a benefit arrangement associated with exit from or disposal of business activities or restructurings pursuant to a duly authorized plan, excluding costs or losses pertaining to an entity newly acquired in a business combination or a discontinued operation as defined by generally accepted accounting principles and costs associated with one-time termination benefits.

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