Notes Payable (Other Information) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Debt Disclosure [Abstract]
Total interest incurred	$ 10,874	$ 11,331
Interest capitalized	(1,096)	(1,590)
Total interest expense	$ 9,778	$ 9,741