Earnings Per Share (Details Textuals)	3 Months Ended	6 Months Ended
Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Earnings Per Share (Textuals) [Abstract]
Options to purchase common stock excluded from computation of dilutive securities	0	0	0	0

Name:

fls_OptionsToPurchaseCommonStockExcludedFromComputationOfDilutiveSecurities

Namespace Prefix:

fls

Data Type:

xbrli:sharesItemType

Balance Type:

na

Period Type:

duration