XML 46 R26.htm IDEA: XBRL DOCUMENT
v3.3.1.900

Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2015
Basis of Presentation and Significant Accounting Policies [Abstract] |
Comprehensive Income (Loss) [Table Text Block] | The changes in the balances of components comprising other comprehensive income (loss) are presented in the following table:
| Derivative Adjustments (1) |  | Pension Liability Adjustments
| (in thousands)
For the year ended December 31, 2013 |  |  |
Net actuarial gain |  |  | $ | 2,766 |
Reclassification to earnings | $ | 1,777 |  |  | 1,239 |
Tax expense | (662 | ) |  | (1,522 | )
Income, net of tax | $ | 1,115 |  |  | $ | 2,483 |
For the year ended December 31, 2014 |  |  |
Net actuarial loss |  |  |  | $ | (10,062 | )
Reclassification to earnings | $ | — |  |  | 706 |
Tax benefit | — |  |  | 3,460 |
Loss, net of tax | $ | — |  |  | $ | (5,896 | )
For the year ended December 31, 2015 |  |  |
Net actuarial loss |  |  | $ | (4,990 | )
Reclassification to earnings | $ | — |  |  | 1,853 |
Tax benefit | — |  |  | 1,047 |
Loss, net of tax | $ | — |  |  | $ | (2,090 | )
____________________________________________
(1) | As of December 31, 2013, all commodity derivative contracts that had been previously designated as cash flow hedges had settled and had been reclassified into earnings from AOCL.
Dilutive and Anti-Dilutive Shares for Earnings per Share [Table Text Block] | The following table details the weighted-average dilutive and anti-dilutive securities related to RSUs, PSUs, and stock options for the years presented:
| For the Years Ended December 31,
| 2015 |  | 2014 |  | 2013
| (in thousands)
Dilutive | — |  |  | 814 |  |  | 1,383 |
Anti-dilutive | 256 |  |  | — |  |  | — |
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] | The following table sets forth the calculations of basic and diluted earnings per share:
| For the Years Ended December 31,
| 2015 |  | 2014 |  | 2013
| (in thousands, except per share amounts)
Net income (loss) | $ | (447,710 | ) |  | $ | 666,051 |  |  | $ | 170,935 |
Basic weighted-average common shares outstanding | 67,723 |  |  | 67,230 |  |  | 66,615 |
Add: dilutive effect of stock options, unvested RSUs, and contingent PSUs (1) | — |  |  | 814 |  |  | 1,383 |
Diluted weighted-average common shares outstanding | 67,723 |  |  | 68,044 |  |  | 67,998 |
Basic net income (loss) per common share | $ | (6.61 | ) |  | $ | 9.91 |  |  | $ | 2.57 |
Diluted net income (loss) per common share | $ | (6.61 | ) |  | $ | 9.79 |  |  | $ | 2.51 |
____________________________________________
(1) | For the year ended December 31, 2015, the shares were anti-dilutive and excluded from the calculation of diluted earnings per share.

X
- Definition Basis of Presentation and Significant Accounting Policies [Abstract] + References No definition available. + Details
Name: | sm_BasisofPresentationandSignificantAccountingPoliciesAbstract
Namespace Prefix: | sm_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Weighted-average dilutive and anti-dilutive securities + References No definition available. + Details
Name: | sm_DilutiveAndAntiDilutiveSharesForEarningsPerShareTableTextBlock
Namespace Prefix: | sm_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of components of comprehensive income (loss). Includes, but is not limited to, foreign currency translation adjustments, foreign currency transactions designated as economic hedges of a net investment in foreign entity, gain (loss) and prior service cost (credit) for pension plans and other postretirement benefit plans. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=36458714&loc=d3e526-108580 + Details
Name: | us-gaap_ScheduleOfComprehensiveIncomeLossTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of an entity's basic and diluted earnings per share calculations, including a reconciliation of numerators and denominators of the basic and diluted per-share computations for income from continuing operations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257 + Details
Name: | us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration