Annual report pursuant to Section 13 and 15(d)

Shareholders' Equity (Repurchase Program and Warrants) (Details)

v2.4.1.9
Shareholders' Equity (Repurchase Program and Warrants) (Details) (USD $)
In Thousands, except Share data, unless otherwise specified
0 Months Ended 12 Months Ended 39 Months Ended
Aug. 15, 2013
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2014
Nov. 30, 2014
Oct. 31, 2011
Mar. 31, 2007
Equity [Abstract]              
Shares authorized for repurchase             2,500,000us-gaap_StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased
Shares authorized for additional repurchase         10,000,000lts_StockRepurchaseProgramNumberOfAdditionalSharesAuthorizedToBeRepurchased 5,000,000lts_StockRepurchaseProgramNumberOfAdditionalSharesAuthorizedToBeRepurchased  
Shares repurchased, shares 3,000,000us-gaap_StockRepurchasedDuringPeriodShares 2,846,395us-gaap_StockRepurchasedDuringPeriodShares   6,596,152us-gaap_StockRepurchasedDuringPeriodShares      
Shares repurchased, value $ 5,010us-gaap_StockRepurchasedDuringPeriodValue $ 9,535us-gaap_StockRepurchasedDuringPeriodValue   $ 15,624us-gaap_StockRepurchasedDuringPeriodValue      
Cost per share $ 1.67us-gaap_TreasuryStockAcquiredAverageCostPerShare            
Warrant exercise   13,333lts_ClassOfWarrantOrRightExercisesInPeriod 1,002,065lts_ClassOfWarrantOrRightExercisesInPeriod        
Shares tendered in payment of exercise price     224,601lts_SharesTenderedinPaymentofExercisePrice        
Intrinsic value of warrant exercised   $ 23lts_ClassOfWarrantOrRightExercisesInPeriodTotalIntrinsicValue $ 2,526lts_ClassOfWarrantOrRightExercisesInPeriodTotalIntrinsicValue