Notes Payable (Other Debt Information) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Debt Disclosure [Abstract]
Notes payable, fair value	$ 1,900,000		$ 1,900,000		$ 1,100,000
Total interest incurred	18,918	$ 11,087	43,928	$ 33,064
Interest capitalized	(4,218)	(1,536)	(6,349)	(4,021)
Total interest expense	$ 14,700	$ 9,551	$ 37,579	$ 29,043