XML 63 R20.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Assets Held for Sale Fair Value of Net Assets Acquired from Baytex (Tables) | 9 Months Ended
--- | ---
Sep. 30, 2014
Fair Value of Net Assets Acquired from Baytex [Abstract] |
Schedule of Fair Value of Net Assets Acquired [Table Text Block] |
Purchase Price | As of September 24, 2014
| (in thousands)
Cash consideration | $ | 325,230 |
Fair value of assets acquired: |
Proved oil and gas properties | $ | 201,842 |
Unproved oil and gas properties | 125,562 |
Total fair value of oil and gas properties acquired | 327,404 |
Working capital | (61 | )
Asset retirement obligation | (2,113 | )
Total fair value of net assets acquired | $ | 325,230 |

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

X
- Definition Schedule of Fair Value of Net Assets Acquired [Table Text Block] + References No definition available. + Details
Name: | sm_ScheduleofFairValueofNetAssetsAcquiredTableTextBlock
Namespace Prefix: | sm_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration