Significant Accounting and Reporting Policies-Receivables (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Allowance for Doubtful Accounts Receivable [Roll Forward]      
Allowance for doubtful accounts, beginning of period $ 10,960 $ 10,234 $ 10,584
Provision for bad debt expense 1,432 2,117 1,396
Write-offs, net of recoveries (684) (812) (2,112)
Currency translation and other changes (868) (579) 366
Adjustments for business acquisitions and dispositions 2,293 0 0
Allowance for doubtful accounts, end of period 13,133 10,960 10,234
Sales allowances, services $ 2,704 $ 1,786 $ 2,812