Annual report pursuant to Section 13 and 15(d)

Income Taxes (Narrative) (Details)

v2.4.1.9
Income Taxes (Narrative) (Details) (USD $)
In Thousands, unless otherwise specified
 3 Months Ended 12 Months Ended
Dec. 31, 2014
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Operating Loss Carryforwards [Line Items]        
U.S. statutory federal income tax rate   35.00%us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate 34.00%us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate 34.00%us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate
Net deferred tax liability $ 21,238us-gaap_DeferredTaxLiabilities $ 21,238us-gaap_DeferredTaxLiabilities    
Reversal of valuation allowance 5,760lts_ReversalofValuationAllowance      
Valuation allowance, reversed and recorded as deferred tax benefit   1,592lts_ValuationAllowanceReversedandRecordedasDeferredTaxBenefit    
Valuation allowance 0us-gaap_DeferredTaxAssetsValuationAllowance 0us-gaap_DeferredTaxAssetsValuationAllowance 28,590us-gaap_DeferredTaxAssetsValuationAllowance [1]  
Net operating loss carryforward 62,000us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsDomestic 62,000us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsDomestic    
Amortization of excess tax goodwill   $ 2,033lts_GoodwillAndIntangibleAssetImpairmentTaxBenefit    
[1] Deferred tax assets net of deferred tax liabilities were decreased $7,801 with a corresponding decrease in the valuation allowance previously recorded.