SCHEDULE II-VALUATION AND QUALIFYING ACCOUNTS (Details) - Allowance for doubtful accounts-accounts receivable - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Changes in allowance for doubtful accounts during the period      
Balance at Beginning of Period $ 5,942 $ 4,818 $ 7,513
Charged to Costs and Expenses 231 1,303 1,700
Recoveries 23 42 277
Write Offs (785) (1,297) (4,672)
Other Adjustment 138 1,076  
Balance at End of Period $ 5,549 $ 5,942 $ 4,818