Interest Expense Incurred (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Interest Costs Incurred [Abstract]
Gross interest	$ 262,238	$ 223,715	$ 186,867
Capitalized interest	(88,563)	(66,220)	(58,222)
Interest Expense	$ 173,675	$ 157,495	$ 128,645