Consolidation and Integration Reserve - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Collaboration Arrangement Disclosure [Abstract]
Lease consolidation and abandonment	$ 478	$ 642	$ 700

Consolidation and integration reserve adjustments that were recorded to operating expenses during the current period.

No definition available.

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