Share-Based Compensation (Compensation Expense of Nonvested Stock Options Not Yet Recognized) (Details) (USD $) In Thousands	6 Months Ended
Jun. 30, 2011
Share-Based Compensation
Remaining six months of 2011	$ 97
2012	95
2013	32
Total	$ 224

Name:

swc_EmployeeServiceShareBasedCompensationNonvestedStockOptionsTotalCompensationCostToBeRecognizedInYearThree

Namespace Prefix:

swc

Data Type:

xbrli:monetaryItemType

Balance Type:

debit

Period Type:

duration