Share-based Compensation Non-employee Directors (Details) (USD $)	Dec. 31, 2012
Outstanding Stock Options for Non-empoyee directors	243,746
Share-based Compensation Arrangement for Non-employee Directors by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price	$ 6.65

The number of non-qualified shares reserved for non-employee directors for issuance under stock option agreements awarded under the plan that validly exist and are outstanding as of the balance sheet date, including vested options.

No definition available.

Name:	spir_OutstandingStockOptionsForNonEmpoyeeDirectors
Namespace Prefix:	spir_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant