Write Downs and Other Charges (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Write Downs And Other Charges [Abstract]      
Write downs and other charges $ 3,262 $ 11,766 $ 7,068
Fees related to acquisition   8,200 2,800
Impairment of intangible assets 3,300 3,400 1,400
Write-off of prepaids   1,300  
Gain (loss) on sale of assets 1,000 1,300 1,900
Impairment of long-lived assets 2,000 200 $ 800
Change in amount of contingent consideration $ (3,000) $ 2,700