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Financial Instruments - Summary of Bond Activity (Detail) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2017 | Dec. 31, 2016
Derivative Instruments And Hedging Activities Disclosure [Abstract] |  |
Fair value at beginning of period | $ 44,573 | $ 43,142
Purchases | 15,546 | 11,355
Sales | (940) | (2,900)
Maturities and calls | (7,845) | (6,878)
Decrease in bond premium | (160) | (106)
Fair market value adjustment | (73) | (40)
Fair value at end of period | $ 51,101 | $ 44,573

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- Definition Fair market value adjustment of bonds. + References No definition available. + Details
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- Definition Financial instrument maturities and calls of corporate and municipal debt. + References No definition available. + Details
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- Definition Financial instrument purchases of corporate and municipal debt. + References No definition available. + Details
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- Definition Financial instrument sales of corporate and municipal debt. + References No definition available. + Details
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Namespace Prefix: | cbz_
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- Definition Increase (Decrease) in bond premium. + References No definition available. + Details
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- References No definition available. + Details
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- Definition Fair value of firm holdings in corporate fixed income securities. Includes pledged and unpledged holdings. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 940 -SubTopic 320 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=35711157&loc=d3e42546-110969 + Details
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