XML 74 R56.htm IDEA: XBRL DOCUMENT v3.8.0.1
Debt - Interest Expense (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Debt Disclosure [Abstract]      
Gross interest cost $ 118,276 $ 133,137 $ 98,103
Capitalized interest (5,656) (2,290) (8,690)
Interest expense $ 112,620 $ 130,847 $ 89,413