Annual and transition report of foreign private issuers pursuant to Section 13 or 15(d)

Income taxes (Reconciliation of statutory income tax expense to provision for income taxes) (Details)

v3.8.0.1
Income taxes (Reconciliation of statutory income tax expense to provision for income taxes) (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Income Tax Disclosure [Abstract]      
Statutory income tax rate 12.50% 12.50% 12.50%
Income tax expense at statutory income tax rate of 12.5% $ 154,484 $ 150,050 $ 170,712
Permanent differences 23,737 [1] 29,057 [2] 29,555 [3]
Foreign rate differential [4] (13,503) (5,611) (10,462)
Differences between statutory and actual income tax expense 10,234 23,446 19,093
Provision for income taxes $ 164,718 $ 173,496 $ 189,805
[1] The 2017 permanent differences included non-deductible share-based compensation in Ireland and in the Netherlands, impacts of the change in tax rate in the United States, and a valuation allowance change in respect of U.S., Dutch and Irish tax losses.
[2] The 2016 permanent differences included non-deductible share-based compensation in Ireland and in the Netherlands, non-deductible intercompany interest allocated to the United States, and a valuation allowance taken in respect of U.S., Dutch and Irish tax losses.
[3] The 2015 permanent differences included the non-deductible intercompany interest allocated to the United States, non-deductible share-based compensation in the Netherlands, non-deductible costs relating to the transfer of certain functions from the Netherlands to Ireland, and a valuation allowance taken in respect of U.S. and Dutch tax losses.
[4] The tax variance as a result of global activities is primarily caused by our operations in countries with a higher or lower statutory tax rate than the statutory tax rate in Ireland.