Long-Term Debt - Total Interest Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Long-term Debt, Unclassified [Abstract]
Cash paid for interest	$ 84,823	$ 142,664	$ 132,995
Change in accrued interest	30,600	(3,834)	7,266
Capitalized interest	(907)	(3,372)	(4,470)
Amortization of loan costs	5,563	6,328	6,121
Total interest expense	$ 120,079	$ 141,786	$ 141,912