Debt - Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Debt Disclosure [Abstract]
Gross interest	$ 33,433	$ 25,029	$ 100,886	$ 69,181
Capitalized interest	(582)	(1,163)	(1,577)	(7,642)
Interest expense	$ 32,851	$ 23,866	$ 99,309	$ 61,539