Represents the additional waiting period for deferred cash awards.

No definition available.

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Data Type:	us-types:durationStringItemType
Balance Type:	na
Period Type:	duration

- Definition

The period of restriction for the sale of shares paid to identified staff in the European Union (EU), as stated in months.

+ References

No definition available.

+ Details

Name:	c_DeferredCompensationArrangementsByPlanTypePeriodOfRestrictionForSaleOfSharesPaidToParticipantsInEuropeanUnion
Namespace Prefix:	c_
Data Type:	us-types:durationStringItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the percentage of deferred portion delivered as a CAP award.

+ References

No definition available.

+ Details

Name:	c_DeferredPortionDeliveredAsCAPAwardPercentage
Namespace Prefix:	c_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the percentage of deferred portion delivered as a deferred cash award.

+ References

No definition available.

+ Details

Name:	c_DeferredPortionDeliveredAsDeferredCashAwardPercentage
Namespace Prefix:	c_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the percentage of incentive pay required to be deferred before rise.

+ References

No definition available.

+ Details

Name:	c_IncentivePayRequiredToBeDeferredBeforeRisePercentage
Namespace Prefix:	c_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the percentage of incentive pay required to be deferred.

+ References

No definition available.

+ Details

Name:	c_IncentivePayRequiredToBeDeferredPercentage
Namespace Prefix:	c_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the annual rate of notional interest on deferred cash award which is compounded annually.

+ References

No definition available.

+ Details

Name:	c_NotionalInterestOnDeferredCashAwardAnnualRate
Namespace Prefix:	c_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(1)(i)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph g(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SAB TOPIC 14.F)

-URI http://asc.fasb.org/extlink&oid=6793087&loc=d3e301413-122809

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 14

-Section F

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph 64

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Name:	us-gaap_AllocatedShareBasedCompensationExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Description of the period of time over which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, which may be expressed in a variety of ways (for example, in years, month and year).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph a

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod
Namespace Prefix:	us-gaap_
Data Type:	us-types:durationStringItemType
Balance Type:	na
Period Type:	duration

- Definition

The minimum vesting term over which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition.

+ References

No definition available.

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriodMinimum
Namespace Prefix:	us-gaap_
Data Type:	us-types:dateStringItemType
Balance Type:	na
Period Type:	duration

- Definition

Description of award terms as to how many shares or portion of an award are no longer contingent on satisfaction of either a service condition, market condition or a performance condition, thereby giving the employee the legal right to convert the award to shares, to sell the shares, and be entitled to the cash proceeds of such sale. For example, vesting may be expressed as being 25 percent of the shares under option on each anniversary of the grant date.

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingRights
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

INCENTIVE PLANS (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		1 Months Ended				6 Months Ended		1 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012 Deferred Cash Program	Jun. 30, 2011 Deferred Cash Program	Jun. 30, 2012 Deferred Cash Program	Jun. 30, 2011 Deferred Cash Program	Jun. 30, 2012 Key Employee Profit Sharing Plan (KEPSP)	Jun. 30, 2011 Key Employee Profit Sharing Plan (KEPSP)	Jun. 30, 2012 Key Employee Profit Sharing Plan (KEPSP)	Jun. 30, 2011 Key Employee Profit Sharing Plan (KEPSP)	Jun. 30, 2012 Other Incentive Compensation	Jun. 30, 2011 Other Incentive Compensation	Jun. 30, 2012 Other Incentive Compensation	Jun. 30, 2011 Other Incentive Compensation	Jan. 31, 2012 2012 Incentive Awards	Jan. 31, 2012 Minimum 2012 Incentive Awards	Jan. 31, 2012 Maximum 2012 Incentive Awards	Jan. 31, 2012 Capital Accumulation Program Awards (CAP)	Jun. 30, 2012 Capital Accumulation Program Awards (CAP) Minimum	Jun. 30, 2012 Capital Accumulation Program Awards (CAP) Maximum	Jan. 31, 2012 Incentive Awards to identified staff in European Union
Incentive Plans
Recognized compensation expense related to equity-based compensation arrangements	$ 296	$ 394	$ 711	$ 769	$ 58	$ 54	$ 135	$ 133	$ 78	$ 97	$ 152	$ 183	$ 26	$ 26	$ 57	$ 59
Percentage of incentive pay required to be deferred before rise																	25.00%
Percentage of incentive pay required to be deferred																		40.00%	60.00%
Percentage of deferred portion delivered as CAP award																	50.00%
Percentage of deferred portion delivered as a deferred cash award																	50.00%
Annual rate of notional interest on deferred cash award																	3.55%
Vesting period, minimum (in years)																					P3Y	P4Y	P3Y
Period of restriction for the sale of shares paid to participants in the European Union (EU) (in months)																							6 months
Additional waiting period for deferred cash awards																							6 months
Vesting rights																				25%
Award vesting period (in years)																				4 years