The basis points added to the reference rate to compute the variable rate on the debt instrument.

Name:	o_DebtInstrumentBasisSpreadOnVariableRateBasisPoints
Namespace Prefix:	o
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of annual (one year) extension options available for a line of credit facility

+ Details

Name:	o_ExtensionOptions
Namespace Prefix:	o
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The total of all basis point fees of the line of credit facility, in the calculation of a variable interest rate before the London Interbank Offered Rate.

+ Details

Name:	o_LineOfCreditFacilityAllInDrawnVariableInterestRateBasisPoints
Namespace Prefix:	o
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The fee, expressed as a basis point of the line of credit facility, for the line of credit facility regardless of whether the facility has been used.

+ Details

Name:	o_LineOfCreditFacilityCommitmentFeeBasisPoints
Namespace Prefix:	o
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Maximum borrowing capacity under a previous credit facility. Facility no longer in place and is replaced by a current credit unsecured credit facility agreement.

+ Details

Name:	o_RevolvingUnsecuredCreditFacilityReplaced
Namespace Prefix:	o
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Reflects when the credit facility terminates, which may be presented in a variety of ways (year, month and year, day, month and year, quarter).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 129
-Paragraph 2, 4
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 19, 22
-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_LineOfCreditFacilityExpirationDate
Namespace Prefix:	us-gaap
Data Type:	us-types:dateStringItemType
Balance Type:	na
Period Type:	duration

- Definition

Reflects when the credit facility first became available, which may be presented in a variety of ways (year, month and year, day, month and year, quarter).

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityInitiationDate
Namespace Prefix:	us-gaap
Data Type:	us-types:dateStringItemType
Balance Type:	na
Period Type:	duration

- Definition

The effective interest rate at the end of the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 19, 22
-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd
Namespace Prefix:	us-gaap
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Description of the interest rate for the amounts borrowed under the credit facility, including the terms and the method for determining the interest rate (for example, fixed or variable, LIBOR plus a percentage, increasing rate, timing of interest rate resets, remarketing provisions).

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityInterestRateDescription
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The effective interest rate during the reporting period.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityInterestRateDuringPeriod
Namespace Prefix:	us-gaap
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ Details

Name:	us-gaap_LineOfCreditFacilityLineItems
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.17)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_UnamortizedDebtIssuanceExpense
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Credit Facility (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended		6 Months Ended
	Jun. 30, 2011 Revolving Unsecured Credit Facility [Member]	Dec. 31, 2010 Revolving Unsecured Credit Facility [Member]	Jun. 30, 2011 RevolvingUnsecuredCreditFacilityMemberReplaced [Member]	Jun. 30, 2010 RevolvingUnsecuredCreditFacilityMemberReplaced [Member]
Line of Credit Facility [Line Items]
Revolving unsecured credit facility	$ 425
Revolving unsecured credit facility, replaced			355
Initiation Date	December 2010
Expiration date	March 2014		May 2011
Available one year extension options	2
Line of Credit Facility, interest rate description	LondonInterbank Offered Rate, commonly referred to as LIBOR, plus 185 basis points with a facility commitment fee of 35 basis points, for all-in drawn pricing of 220 basis points over LIBOR. The borrowing rate is not subject to an interest rate floor or ceiling
Variable interest rate, LIBOR plus basis points	185
Line of credit facility, commitment fee basis points	35
Line of credit facility all-in drawn variable interest rate	220
Unamortized debt issuance expense	$ 3.5	$ 4.2
Average borrowing rate during period	2.10%			1.30%
Borrowing rate, period end	2.00%			1.30%