Goodwill and Other Intangible Assets, Net - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2012
Goodwill And Intangible Assets Disclosure [Abstract]
Reduction in the value of goodwill	$ 1.4

Amount of change to goodwill as a result of purchase price adjustments related to business acquisitions.

No definition available.

Name:	cbz_BusinessAcquisitionsPurchasePriceAdjustment
Namespace Prefix:	cbz_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration