Long-Term Debt - Interest Expense And Capitalized Interest (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Debt Disclosure [Abstract]
Interest expense	$ 31,186	$ 32,617	$ 38,274
Capitalized interest	(20,246)	(15,629)	(16,906)
Interest income	(2,607)	(3,237)	(2,590)
Net interest expense	$ 8,333	$ 13,751	$ 18,778