Annual report pursuant to Section 13 and 15(d)

Income Taxes - Income Tax Reconciliation (Details)

v3.8.0.1
Income Taxes - Income Tax Reconciliation (Details) - USD ($)
$ in Thousands
3 Months Ended 12 Months Ended
Dec. 31, 2017
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Income Tax Disclosure [Abstract]        
Income tax at federal statutory rate   $ 15,200 $ 22,427 $ 16,250
Effect of permanent differences   459 12,496 370
TaxcutsandjobsactTransitionTax   20,792 0 0
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount $ 1,000 954 0 0
Change in valuation allowance   (43) (3,877) 2,017
Foreign rate differential   (15,002) (21,713) (18,099)
Effective Income Tax Rate Reconciliation, Tax Credit, Other, Amount   (2,105) (261) 0
Other reconciling items   (407) (81) 14
Income tax provision   $ 19,848 $ 8,991 $ 552