Annual report pursuant to Section 13 and 15(d)

CONSOLIDATED BALANCE SHEETS (Parenthetical)

v2.4.1.9
CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)
Dec. 31, 2014
Dec. 31, 2013
Trade accounts receivable, allowances $ 12,727,000us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent $ 10,809,000us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent
Inventories, reserves 1,227,000us-gaap_InventoryValuationReserves  
Notes receivable, allowance 539,000us-gaap_AllowanceForNotesAndLoansReceivableNoncurrent 548,000us-gaap_AllowanceForNotesAndLoansReceivableNoncurrent
Property and equipment, accumulated depreciation 155,495,000us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment 145,215,000us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment
Amortizable intangible assets, accumulated amortization $ 34,130,000us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization $ 27,933,000us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization
Treasury stock, shares 2,317,650us-gaap_TreasuryStockShares 2,317,650us-gaap_TreasuryStockShares
Class A Common Stock [Member]    
Common stock, par value $ 0.01us-gaap_CommonStockParOrStatedValuePerShare
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
$ 0.01us-gaap_CommonStockParOrStatedValuePerShare
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
Common stock, authorized 80,000,000us-gaap_CommonStockSharesAuthorized
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
80,000,000us-gaap_CommonStockSharesAuthorized
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
Common stock, issued 22,082,140us-gaap_CommonStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
21,803,303us-gaap_CommonStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
Common stock, outstanding 19,764,490us-gaap_CommonStockSharesOutstanding
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
19,485,653us-gaap_CommonStockSharesOutstanding
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
Class B Common Stock [Member]    
Common stock, par value $ 0.01us-gaap_CommonStockParOrStatedValuePerShare
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
$ 0.01us-gaap_CommonStockParOrStatedValuePerShare
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
Common stock, authorized 20,000,000us-gaap_CommonStockSharesAuthorized
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
20,000,000us-gaap_CommonStockSharesAuthorized
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
Common stock, issued 5,553,696us-gaap_CommonStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
5,553,696us-gaap_CommonStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
Common stock, outstanding 5,553,696us-gaap_CommonStockSharesOutstanding
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
5,553,696us-gaap_CommonStockSharesOutstanding
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember