Contingencies - Additional Information (Detail) (USD $)	1 Months Ended	12 Months Ended
Sep. 17, 2012	Dec. 31, 2012	Dec. 31, 2010
Operating and Capital Leases [Line Items]
Payments to civil penalty	$ 3,700,000
Litigation settlement expense			6,500
Compensatory and punitive damages		$ 270,000,000
Number Of Corporate Operated Centers		87

The value (monetary amount) of the award the plaintiff seeks in the legal matter.

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+ Details