Quarterly report pursuant to Section 13 or 15(d)

Income Taxes - Additional Information (Details)

v3.10.0.1
Income Taxes - Additional Information (Details) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2009
Sep. 30, 2018
Sep. 30, 2017
Sep. 30, 2018
Sep. 30, 2017
Valuation Allowance [Line Items]                      
Income tax provision (benefit)               $ (2,050) $ (6,276) $ 7,311 $ (33,770)
Unrecognized Tax Benefits, Period Increase (Decrease)                   500  
Unrecognized Tax Benefits, Interest on Income Taxes Accrued               800   800  
Unrecognized Tax Benefits, Income Tax Penalties Accrued               $ 200   $ 200  
Domestic Tax Authority [Member]                      
Valuation Allowance [Line Items]                      
Open Tax Year         2013            
State and Local Jurisdiction [Member]                      
Valuation Allowance [Line Items]                      
Open Tax Year           2012          
Income Tax Examination, Year under Examination     2015 2014              
Foreign Tax Authority [Member]                      
Valuation Allowance [Line Items]                      
Open Tax Year             2009        
Income Tax Examination, Year under Examination 2017 2016                  
Minimum [Member]                      
Valuation Allowance [Line Items]                      
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent                   21.00%  
Maximum [Member]                      
Valuation Allowance [Line Items]                      
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent                   35.00%