Long-Term Debt - Components Of Net Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Debt Disclosure [Abstract]
Interest expense	$ 5,943	$ 7,179	$ 12,055	$ 14,573
Capitalized interest				(1,182)
Interest income	(24)	(116)	(83)	(582)
Net interest expense	$ 5,919	$ 7,063	$ 11,972	$ 12,809