XML 56 R27.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Assets Held for Sale (Details) (USD $) | 3 Months Ended |  |
--- | --- | --- | ---
Mar. 31, 2014 | Apr. 23, 2014 | Dec. 31, 2013
Assets held for sale [Abstract] |  |  |
Cash Consideration to Acquire Unproved Property |  | $ 100,000,000 |
Leasehold Acres Consideration to Acquire Unproved Property |  | 7,000 |
Assets Held-for-sale Reasonably Certain Period for Sale | 1 |  |
Oil and gas properties held for sale net of accumulated depletion, depreciation and amortization of $31,776 in 2014 and $7,390 in 2013 | 42,276,000 |  | 19,072,000
Asset retirement obligation associated with oil and gas properties held for sale | $ 4,526,000 |  | $ 3,033,000

X
- Definition Noncurrent portion of the carrying amount of a liability for an asset retirement obligation for an asset held for sale. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees. + References No definition available. + Details
Name: | sm_AssetRetirementObligationsAssetsHeldForSaleNoncurrent
Namespace Prefix: | sm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | sm_AssetsheldforsaleAbstract
Namespace Prefix: | sm_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the period where there is reasonable certainty that the sale will take place for the assets to be classified as held for sale. + References No definition available. + Details
Name: | sm_AssetsHeldforsaleReasonablyCertainPeriodforSale
Namespace Prefix: | sm_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Cash Consideration to Acquire Unproved Property + References No definition available. + Details
Name: | sm_CashConsiderationtoAcquireUnprovedProperty
Namespace Prefix: | sm_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Leasehold Acres Consideration to Acquire Unproved Property + References No definition available. + Details
Name: | sm_LeaseholdAcresConsiderationtoAcquireUnprovedProperty
Namespace Prefix: | sm_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Long-lived assets that are held for sale apart from normal operations and anticipated to be sold in less than one year. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 45 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=6892542&loc=d3e1107-107759 + Details
Name: | us-gaap_AssetsHeldForSaleLongLived
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant