XML 44 R40.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Business Segments (Narrative) (Details) | 3 Months Ended
--- | ---
Mar. 31, 2014
Business Segments [Abstract] |
Capital Charges Rate | 1.00%
Segment Reporting, Measurement for Transactions Between Reportable Segments | Segment profits from continuing operations, as shown above, include internal cost of capital charges for assets used in the segment at a rate of generally 1% per month. There has been no change in the measurement of segment profit from continuing operations from December 31, 2013. The internal cost of capital charges are eliminated during the consolidation process.

X
- Definition The internal cost of capital rate charged to a segment for assets used by the segment. + References No definition available. + Details
Name: | fstr_CapitalChargesRate
Namespace Prefix: | fstr_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition A description of the basis of accounting for transactions between reportable segments. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 29 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6534315&loc=d3e8864-108599 + Details
Name: | us-gaap_DescriptionOfBasisOfAccountingForTransactionsBetweenReportableSegments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_SegmentReportingDisclosureOfEntitysReportableSegmentsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration