Long-Term Debt - Interest Expense And Capitalized Interest (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Debt Disclosure [Abstract]
Interest expense	$ 30,538	$ 31,186	$ 32,617
Capitalized interest (1)	(1,182)	(20,246)	(15,629)
Interest income	(825)	(2,607)	(3,237)
Net interest expense	$ 28,531	$ 8,333	$ 13,751