Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Interest Expense
Interest expense before capitalized interest	$ 16,666	$ 16,554
Amortization of deferred financing costs	1,047	622
Interest expense related to finance lease right-of-use assets	426	144
Net unrealized gain on derivative financial instruments not designated as cash flow hedges	(133)	(47)
Capitalized interest	(1,710)	(5,268)
Interest expense	$ 16,296	$ 12,005