Disclousres about Fair Value of Financial Instruments and Concentrations of Credit Risk - Additional Information (Detail)	Dec. 31, 2011	Dec. 31, 2010
Fair Value, Measurement Inputs, Disclosure [Line Items]
Percentage of consolidated trade receivables accounted by single customer	17.00%	21.00%

Percentage of consolidated trade receivables accounted by single customer.

No definition available.

Name:	caj_PercentageOfTotalTradeReceivables
Namespace Prefix:	caj_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant