Quarterly report pursuant to Section 13 or 15(d)

Supplemental Cash Flow Information (Details)

v3.10.0.1
Supplemental Cash Flow Information (Details) - USD ($)
$ in Thousands
6 Months Ended
Jun. 30, 2018
Jun. 30, 2017
Cash paid during the period for:    
Income taxes $ 11,053 $ 15,904
Interest 60,210 91,710
Non-cash investing activity:    
Capital expenditures acquired on account but unpaid as of the period end $ 11,875 $ 11,681