Long-Term Debt - Components Of Net Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Debt Disclosure [Abstract]
Interest expense	$ 8,007	$ 7,694	$ 22,580	$ 23,635
Interest income	(409)	(652)	(991)	(2,085)
Capitalized interest	0	(5,141)	(1,182)	(15,346)
Net interest expense	$ 7,598	$ 1,901	$ 20,407	$ 6,204