Summary Of Major Accounting Policies - Property, Plant and Equipment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Accounting Policies [Abstract]
Interest Costs, Capitalized During Period	$ 1,831	$ 1,200	$ 3,409	$ 2,155