Long-Term Debt (Net Interest Expense) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Debt Disclosure [Abstract]
Interest expense	$ 10,897	$ 8,952	$ 29,057	$ 24,474
Interest income	(470)	(2,741)	(1,577)	(4,113)
Capitalized interest	(1,714)	(2,355)	(9,462)	(7,505)
Net interest expense	$ 8,713	$ 3,856	$ 18,018	$ 12,856